diff --git a/.github/release-please.yml b/.github/release-please.yml
index 466597e5..29601ad4 100644
--- a/.github/release-please.yml
+++ b/.github/release-please.yml
@@ -1,2 +1,11 @@
 releaseType: python
 handleGHRelease: true
+# NOTE: this section is generated by synthtool.languages.python
+# See https://github.com/googleapis/synthtool/blob/master/synthtool/languages/python.py
+branches:
+- branch: v1
+  handleGHRelease: true
+  releaseType: python
+- branch: v0
+  handleGHRelease: true
+  releaseType: python
diff --git a/.github/sync-repo-settings.yaml b/.github/sync-repo-settings.yaml
index 49c96ed4..b06a42ac 100644
--- a/.github/sync-repo-settings.yaml
+++ b/.github/sync-repo-settings.yaml
@@ -16,11 +16,6 @@ branchProtectionRules:
     - 'unit-3.8'
     - 'unit-3.9'
     - 'unit-3.10'
-    - 'unit_grpc_gcp-3.6'
-    - 'unit_grpc_gcp-3.7'
-    - 'unit_grpc_gcp-3.8'
-    - 'unit_grpc_gcp-3.9'
-    - 'unit_grpc_gcp-3.10'
     - 'unit_wo_grpc-3.6'
     - 'unit_wo_grpc-3.10'
     - 'cover'
diff --git a/.github/workflows/unittest.yml b/.github/workflows/unittest.yml
index 77bfc2cc..0c2e37f6 100644
--- a/.github/workflows/unittest.yml
+++ b/.github/workflows/unittest.yml
@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        option: ["", "_grpc_gcp", "_wo_grpc"]
+        option: ["", "_wo_grpc"]
         python:
           - "3.6"
           - "3.7"
diff --git a/CHANGELOG.md b/CHANGELOG.md
index c84458ba..16e22ab8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,21 @@
 
 [1]: https://pypi.org/project/google-api-core/#history
 
-### [2.8.1](https://github.com/googleapis/python-api-core/compare/v2.8.0...v2.8.1) (2022-05-26)
+## [2.8.2](https://github.com/googleapis/python-api-core/compare/v2.8.1...v2.8.2) (2022-06-13)
+
+
+### Bug Fixes
+
+* **deps:** allow protobuf < 5.0.0 ([#400](https://github.com/googleapis/python-api-core/issues/400)) ([8f73d2e](https://github.com/googleapis/python-api-core/commit/8f73d2ee2d3af2201f877aa7e2f7361147759dc7))
+* drop support for grpc-gcp ([#401](https://github.com/googleapis/python-api-core/issues/401)) ([5da6733](https://github.com/googleapis/python-api-core/commit/5da6733a475c436efc11b14889af73b3a0e20379))
+
+
+### Documentation
+
+* fix changelog header to consistent size ([#394](https://github.com/googleapis/python-api-core/issues/394)) ([ac266e9](https://github.com/googleapis/python-api-core/commit/ac266e935bc4e7c6dff250384407e7a60d8dba90))
+* Fix typo in the BackgroundConsumer docstring ([#395](https://github.com/googleapis/python-api-core/issues/395)) ([0eb727f](https://github.com/googleapis/python-api-core/commit/0eb727f92314db3c4383754514f75a49ba02e27b))
+
+## [2.8.1](https://github.com/googleapis/python-api-core/compare/v2.8.0...v2.8.1) (2022-05-26)
 
 
 ### Bug Fixes
@@ -20,14 +34,14 @@
 * adds support for audience in client_options ([#379](https://github.com/googleapis/python-api-core/issues/379)) ([c97c498](https://github.com/googleapis/python-api-core/commit/c97c4980125a86f384cdf12720df7bb1a2adf9d2))
 * adds support for audience in client_options. ([c97c498](https://github.com/googleapis/python-api-core/commit/c97c4980125a86f384cdf12720df7bb1a2adf9d2))
 
-### [2.7.3](https://github.com/googleapis/python-api-core/compare/v2.7.2...v2.7.3) (2022-04-29)
+## [2.7.3](https://github.com/googleapis/python-api-core/compare/v2.7.2...v2.7.3) (2022-04-29)
 
 
 ### Bug Fixes
 
 * Avoid AttributeError if grpcio-status is not installed ([#370](https://github.com/googleapis/python-api-core/issues/370)) ([022add1](https://github.com/googleapis/python-api-core/commit/022add16266f9c07f0f88eea13472cc2e0bfc991))
 
-### [2.7.2](https://github.com/googleapis/python-api-core/compare/v2.7.1...v2.7.2) (2022-04-13)
+## [2.7.2](https://github.com/googleapis/python-api-core/compare/v2.7.1...v2.7.2) (2022-04-13)
 
 
 ### Bug Fixes
@@ -35,7 +49,7 @@
 * allow grpc without grpcio-status ([#355](https://github.com/googleapis/python-api-core/issues/355)) ([112049e](https://github.com/googleapis/python-api-core/commit/112049e79f5a5b0a989d85d438a1bd29485f46f7))
 * remove dependency on pkg_resources ([#361](https://github.com/googleapis/python-api-core/issues/361)) ([523dbd0](https://github.com/googleapis/python-api-core/commit/523dbd0b10d37ffcf83fa751f0bad313f162abf1))
 
-### [2.7.1](https://github.com/googleapis/python-api-core/compare/v2.7.0...v2.7.1) (2022-03-09)
+## [2.7.1](https://github.com/googleapis/python-api-core/compare/v2.7.0...v2.7.1) (2022-03-09)
 
 
 ### Bug Fixes
@@ -49,7 +63,7 @@
 
 * expose extra fields in ExtendedOperation ([#351](https://github.com/googleapis/python-api-core/issues/351)) ([9abc6f4](https://github.com/googleapis/python-api-core/commit/9abc6f48f23c87b9771dca3c96b4f6af39620a50))
 
-### [2.6.1](https://github.com/googleapis/python-api-core/compare/v2.6.0...v2.6.1) (2022-03-05)
+## [2.6.1](https://github.com/googleapis/python-api-core/compare/v2.6.0...v2.6.1) (2022-03-05)
 
 
 ### Bug Fixes
@@ -113,14 +127,14 @@
 
 * handle bare 'grpc.Call' in 'from_grpc_error' ([#298](https://www.github.com/googleapis/python-api-core/issues/298)) ([060b339](https://www.github.com/googleapis/python-api-core/commit/060b339e3af296dd1772bfc1b4a0d2b4264cae1f))
 
-### [2.2.2](https://www.github.com/googleapis/python-api-core/compare/v2.2.1...v2.2.2) (2021-11-02)
+## [2.2.2](https://www.github.com/googleapis/python-api-core/compare/v2.2.1...v2.2.2) (2021-11-02)
 
 
 ### Bug Fixes
 
 * make 'gapic_v1.method.DEFAULT' a typed object ([#292](https://www.github.com/googleapis/python-api-core/issues/292)) ([ffc51f0](https://www.github.com/googleapis/python-api-core/commit/ffc51f03c7ce5d9f009ba859b8df385d52925578))
 
-### [2.2.1](https://www.github.com/googleapis/python-api-core/compare/v2.2.0...v2.2.1) (2021-10-26)
+## [2.2.1](https://www.github.com/googleapis/python-api-core/compare/v2.2.0...v2.2.1) (2021-10-26)
 
 
 ### Bug Fixes
@@ -134,7 +148,7 @@
 
 * add 'GoogleAPICallError.error_details' property ([#286](https://www.github.com/googleapis/python-api-core/issues/286)) ([ef6f0fc](https://www.github.com/googleapis/python-api-core/commit/ef6f0fcfdfe771172056e35e3c990998b3b00416))
 
-### [2.1.1](https://www.github.com/googleapis/python-api-core/compare/v2.1.0...v2.1.1) (2021-10-13)
+## [2.1.1](https://www.github.com/googleapis/python-api-core/compare/v2.1.0...v2.1.1) (2021-10-13)
 
 
 ### Bug Fixes
@@ -150,7 +164,7 @@
 * Add helper function to format query_params for rest transport. ([#275](https://www.github.com/googleapis/python-api-core/issues/275)) ([1c5eb4d](https://www.github.com/googleapis/python-api-core/commit/1c5eb4df93d78e791082d9282330ebf0faacd222))
 * add support for Python 3.10 ([#284](https://www.github.com/googleapis/python-api-core/issues/284)) ([a422a5d](https://www.github.com/googleapis/python-api-core/commit/a422a5d72cb6f363d57e7a4effe421ba8e049cde))
 
-### [2.0.1](https://www.github.com/googleapis/python-api-core/compare/v2.0.0...v2.0.1) (2021-08-31)
+## [2.0.1](https://www.github.com/googleapis/python-api-core/compare/v2.0.0...v2.0.1) (2021-08-31)
 
 
 ### Bug Fixes
@@ -179,7 +193,7 @@
 
 * strip trailing _ from field mask paths ([#228](https://www.github.com/googleapis/python-api-core/issues/228)) ([ff6ef1b](https://www.github.com/googleapis/python-api-core/commit/ff6ef1bd07fa68307b7c82c910416d770e7b3416))
 
-### [1.31.1](https://www.github.com/googleapis/python-api-core/compare/v1.31.0...v1.31.1) (2021-07-26)
+## [1.31.1](https://www.github.com/googleapis/python-api-core/compare/v1.31.0...v1.31.1) (2021-07-26)
 
 
 ### Bug Fixes
@@ -242,7 +256,7 @@
 * Add support for `rest/` token in `x-goog-api-client` header ([#189](https://www.github.com/googleapis/python-api-core/issues/189)) ([15aca6b](https://www.github.com/googleapis/python-api-core/commit/15aca6b288b2ec5ce0251e442e1dfa7f52e1b124))
 * retry google.auth TransportError and requests ConnectionError ([#178](https://www.github.com/googleapis/python-api-core/issues/178)) ([6ae04a8](https://www.github.com/googleapis/python-api-core/commit/6ae04a8d134fffe13f06081e15f9723c1b2ea334))
 
-### [1.26.3](https://www.github.com/googleapis/python-api-core/compare/v1.26.2...v1.26.3) (2021-03-25)
+## [1.26.3](https://www.github.com/googleapis/python-api-core/compare/v1.26.2...v1.26.3) (2021-03-25)
 
 
 ### Bug Fixes
@@ -254,14 +268,14 @@
 
 * update python contributing guide ([#147](https://www.github.com/googleapis/python-api-core/issues/147)) ([1d76b57](https://www.github.com/googleapis/python-api-core/commit/1d76b57d1f218f7885f85dc7c052bad1ad3857ac))
 
-### [1.26.2](https://www.github.com/googleapis/python-api-core/compare/v1.26.1...v1.26.2) (2021-03-23)
+## [1.26.2](https://www.github.com/googleapis/python-api-core/compare/v1.26.1...v1.26.2) (2021-03-23)
 
 
 ### Bug Fixes
 
 * save empty IAM policy bindings ([#155](https://www.github.com/googleapis/python-api-core/issues/155)) ([536c2ca](https://www.github.com/googleapis/python-api-core/commit/536c2cad814b8fa8cd346a3d7bd5f6b9889c4a6f))
 
-### [1.26.1](https://www.github.com/googleapis/python-api-core/compare/v1.26.0...v1.26.1) (2021-02-12)
+## [1.26.1](https://www.github.com/googleapis/python-api-core/compare/v1.26.0...v1.26.1) (2021-02-12)
 
 
 ### Bug Fixes
@@ -275,7 +289,7 @@
 
 * allow default_host and default_scopes to be passed to create_channel ([#134](https://www.github.com/googleapis/python-api-core/issues/134)) ([94c76e0](https://www.github.com/googleapis/python-api-core/commit/94c76e0873e5b2f42331d5b1ad286c1e63b61395))
 
-### [1.25.1](https://www.github.com/googleapis/python-api-core/compare/v1.25.0...v1.25.1) (2021-01-25)
+## [1.25.1](https://www.github.com/googleapis/python-api-core/compare/v1.25.0...v1.25.1) (2021-01-25)
 
 
 ### Bug Fixes
@@ -299,7 +313,7 @@
 
 * **python:** document adding Python 3.9 support, dropping 3.5 support ([#120](https://www.github.com/googleapis/python-api-core/issues/120)) ([b51b7f5](https://www.github.com/googleapis/python-api-core/commit/b51b7f587042fe9340371c1b5c8e9adf8001c43a)), closes [#787](https://www.github.com/googleapis/python-api-core/issues/787)
 
-### [1.24.1](https://www.github.com/googleapis/python-api-core/compare/v1.24.0...v1.24.1) (2020-12-16)
+## [1.24.1](https://www.github.com/googleapis/python-api-core/compare/v1.24.0...v1.24.1) (2020-12-16)
 
 
 ### Bug Fixes
@@ -332,28 +346,28 @@
 * harden install to use full paths, and windows separators on windows ([#88](https://www.github.com/googleapis/python-api-core/issues/88)) ([db8e636](https://www.github.com/googleapis/python-api-core/commit/db8e636f545a8872f959e3f403cfec30ffed6c34))
 * update out-of-date comment in exceptions.py ([#93](https://www.github.com/googleapis/python-api-core/issues/93)) ([70ebe42](https://www.github.com/googleapis/python-api-core/commit/70ebe42601b3d088b3421233ef7d8245229b7265))
 
-### [1.22.4](https://www.github.com/googleapis/python-api-core/compare/v1.22.3...v1.22.4) (2020-10-05)
+## [1.22.4](https://www.github.com/googleapis/python-api-core/compare/v1.22.3...v1.22.4) (2020-10-05)
 
 
 ### Bug Fixes
 
 * use version.py instead of pkg_resources.get_distribution ([#80](https://www.github.com/googleapis/python-api-core/issues/80)) ([d480d97](https://www.github.com/googleapis/python-api-core/commit/d480d97e41cd6705325b3b649360553a83c23f47))
 
-### [1.22.3](https://www.github.com/googleapis/python-api-core/compare/v1.22.2...v1.22.3) (2020-10-02)
+## [1.22.3](https://www.github.com/googleapis/python-api-core/compare/v1.22.2...v1.22.3) (2020-10-02)
 
 
 ### Bug Fixes
 
 * **deps:** require six >= 1.13.0 ([#78](https://www.github.com/googleapis/python-api-core/issues/78)) ([a7a8b98](https://www.github.com/googleapis/python-api-core/commit/a7a8b98602a3eb277fdc607ac69f3bcb147f3351)), closes [/github.com/benjaminp/six/blob/c0be8815d13df45b6ae471c4c436cce8c192245d/CHANGES#L30-L31](https://www.github.com/googleapis//github.com/benjaminp/six/blob/c0be8815d13df45b6ae471c4c436cce8c192245d/CHANGES/issues/L30-L31)
 
-### [1.22.2](https://www.github.com/googleapis/python-api-core/compare/v1.22.1...v1.22.2) (2020-09-03)
+## [1.22.2](https://www.github.com/googleapis/python-api-core/compare/v1.22.1...v1.22.2) (2020-09-03)
 
 
 ### Bug Fixes
 
 * only add quota project id if supported ([#75](https://www.github.com/googleapis/python-api-core/issues/75)) ([8f8ee78](https://www.github.com/googleapis/python-api-core/commit/8f8ee7879e4f834f3c676e535ffc41b5b9b2de62))
 
-### [1.22.1](https://www.github.com/googleapis/python-api-core/compare/v1.22.0...v1.22.1) (2020-08-12)
+## [1.22.1](https://www.github.com/googleapis/python-api-core/compare/v1.22.0...v1.22.1) (2020-08-12)
 
 
 ### Documentation
@@ -384,7 +398,7 @@
 
 * allow credentials files to be passed for channel creation ([#50](https://www.github.com/googleapis/python-api-core/issues/50)) ([ded92d0](https://www.github.com/googleapis/python-api-core/commit/ded92d0acdcde4295d0e5df05fda0d83783a3991))
 
-### [1.20.1](https://www.github.com/googleapis/python-api-core/compare/v1.20.0...v1.20.1) (2020-06-16)
+## [1.20.1](https://www.github.com/googleapis/python-api-core/compare/v1.20.0...v1.20.1) (2020-06-16)
 
 
 ### Bug Fixes
@@ -398,7 +412,7 @@
 
 * allow disabling response stream pre-fetch ([#30](https://www.github.com/googleapis/python-api-core/issues/30)) ([74e0b0f](https://www.github.com/googleapis/python-api-core/commit/74e0b0f8387207933c120af15b2bb5d175dd8f84)), closes [#25](https://www.github.com/googleapis/python-api-core/issues/25)
 
-### [1.19.1](https://www.github.com/googleapis/python-api-core/compare/v1.19.0...v1.19.1) (2020-06-06)
+## [1.19.1](https://www.github.com/googleapis/python-api-core/compare/v1.19.0...v1.19.1) (2020-06-06)
 
 
 ### Bug Fixes
diff --git a/google/api_core/bidi.py b/google/api_core/bidi.py
index 4b4963f7..57f5f9dd 100644
--- a/google/api_core/bidi.py
+++ b/google/api_core/bidi.py
@@ -364,7 +364,7 @@ class ResumableBidiRpc(BidiRpc):
         def should_recover(exc):
             return (
                 isinstance(exc, grpc.RpcError) and
-                exc.code() == grpc.StatusCode.UNVAILABLE)
+                exc.code() == grpc.StatusCode.UNAVAILABLE)
 
         initial_request = example_pb2.StreamingRpcRequest(
             setting='example')
@@ -589,7 +589,7 @@ class BackgroundConsumer(object):
         def should_recover(exc):
             return (
                 isinstance(exc, grpc.RpcError) and
-                exc.code() == grpc.StatusCode.UNVAILABLE)
+                exc.code() == grpc.StatusCode.UNAVAILABLE)
 
         initial_request = example_pb2.StreamingRpcRequest(
             setting='example')
diff --git a/google/api_core/grpc_helpers.py b/google/api_core/grpc_helpers.py
index db16f6fc..47d27726 100644
--- a/google/api_core/grpc_helpers.py
+++ b/google/api_core/grpc_helpers.py
@@ -25,13 +25,6 @@
 import google.auth.transport.grpc
 import google.auth.transport.requests
 
-try:
-    import grpc_gcp
-
-    HAS_GRPC_GCP = True
-except ImportError:
-    HAS_GRPC_GCP = False
-
 
 # The list of gRPC Callable interfaces that return iterators.
 _STREAM_WRAP_CLASSES = (grpc.UnaryStreamMultiCallable, grpc.StreamStreamMultiCallable)
@@ -282,8 +275,7 @@ def create_channel(
         default_scopes (Sequence[str]): Default scopes passed by a Google client
             library. Use 'scopes' for user-defined scopes.
         default_host (str): The default endpoint. e.g., "pubsub.googleapis.com".
-        kwargs: Additional key-word args passed to
-            :func:`grpc_gcp.secure_channel` or :func:`grpc.secure_channel`.
+        kwargs: Additional key-word args passed to :func:`grpc.secure_channel`.
 
     Returns:
         grpc.Channel: The created channel.
@@ -302,12 +294,7 @@ def create_channel(
         default_host=default_host,
     )
 
-    if HAS_GRPC_GCP:
-        # If grpc_gcp module is available use grpc_gcp.secure_channel,
-        # otherwise, use grpc.secure_channel to create grpc channel.
-        return grpc_gcp.secure_channel(target, composite_credentials, **kwargs)
-    else:
-        return grpc.secure_channel(target, composite_credentials, **kwargs)
+    return grpc.secure_channel(target, composite_credentials, **kwargs)
 
 
 _MethodCall = collections.namedtuple(
diff --git a/google/api_core/grpc_helpers_async.py b/google/api_core/grpc_helpers_async.py
index 452e7871..63a3ad18 100644
--- a/google/api_core/grpc_helpers_async.py
+++ b/google/api_core/grpc_helpers_async.py
@@ -27,9 +27,6 @@
 from google.api_core import exceptions, grpc_helpers
 
 
-# TODO(lidiz) Support gRPC GCP wrapper
-HAS_GRPC_GCP = False
-
 # NOTE(lidiz) Alternatively, we can hack "__getattribute__" to perform
 # automatic patching for us. But that means the overhead of creating an
 # extra Python function spreads to every single send and receive.
diff --git a/google/api_core/version.py b/google/api_core/version.py
index 7e8f51a6..839a77a1 100644
--- a/google/api_core/version.py
+++ b/google/api_core/version.py
@@ -12,4 +12,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-__version__ = "2.8.1"
+__version__ = "2.8.2"
diff --git a/noxfile.py b/noxfile.py
index c9333219..9b71610c 100644
--- a/noxfile.py
+++ b/noxfile.py
@@ -32,7 +32,6 @@
 # 'docfx' is excluded since it only needs to run in 'docs-presubmit'
 nox.options.sessions = [
     "unit",
-    "unit_grpc_gcp",
     "unit_wo_grpc",
     "cover",
     "pytype",
@@ -143,18 +142,6 @@ def unit(session):
     default(session)
 
 
-@nox.session(python=["3.6", "3.7", "3.8", "3.9", "3.10"])
-def unit_grpc_gcp(session):
-    """Run the unit test suite with grpcio-gcp installed."""
-    constraints_path = str(
-        CURRENT_DIRECTORY / "testing" / f"constraints-{session.python}.txt"
-    )
-    # Install grpcio-gcp
-    session.install("-e", ".[grpcgcp]", "-c", constraints_path)
-
-    default(session)
-
-
 @nox.session(python=["3.6", "3.10"])
 def unit_wo_grpc(session):
     """Run the unit test suite w/o grpcio installed"""
@@ -173,14 +160,14 @@ def lint_setup_py(session):
 @nox.session(python="3.6")
 def pytype(session):
     """Run type-checking."""
-    session.install(".[grpc, grpcgcp]", "pytype >= 2019.3.21")
+    session.install(".[grpc]", "pytype >= 2019.3.21")
     session.run("pytype")
 
 
 @nox.session(python=DEFAULT_PYTHON_VERSION)
 def mypy(session):
     """Run type-checking."""
-    session.install(".[grpc, grpcgcp]", "mypy")
+    session.install(".[grpc]", "mypy")
     session.install(
         "types-setuptools",
         "types-requests",
@@ -207,7 +194,7 @@ def cover(session):
 def docs(session):
     """Build the docs for this library."""
 
-    session.install("-e", ".[grpc, grpcgcp]")
+    session.install("-e", ".[grpc]")
     session.install("sphinx==4.0.1", "alabaster", "recommonmark")
 
     shutil.rmtree(os.path.join("docs", "_build"), ignore_errors=True)
diff --git a/owlbot.py b/owlbot.py
index 0b7f7d21..9d58f4a1 100644
--- a/owlbot.py
+++ b/owlbot.py
@@ -16,6 +16,7 @@
 
 import synthtool as s
 from synthtool import gcp
+from synthtool.languages import python
 
 common = gcp.CommonTemplates()
 
@@ -47,5 +48,6 @@
 
 s.replace(".github/workflows/lint.yml", "python-version: \"3.10\"", "python-version: \"3.7\"")
 
+python.configure_previous_major_version_branches()
 
 s.shell.run(["nox", "-s", "blacken"], hide_output=False)
diff --git a/setup.py b/setup.py
index 70b26c92..3c40548d 100644
--- a/setup.py
+++ b/setup.py
@@ -30,14 +30,12 @@
 release_status = "Development Status :: 5 - Production/Stable"
 dependencies = [
     "googleapis-common-protos >= 1.56.2, < 2.0dev",
-    "protobuf >= 3.15.0, <4.0.0dev",
+    "protobuf >= 3.15.0, <5.0.0dev",
     "google-auth >= 1.25.0, < 3.0dev",
     "requests >= 2.18.0, < 3.0.0dev",
 ]
 extras = {
     "grpc": ["grpcio >= 1.33.2, < 2.0dev", "grpcio-status >= 1.33.2, < 2.0dev"],
-    "grpcgcp": "grpcio-gcp >= 0.2.2, < 1.0dev",
-    "grpcio-gcp": "grpcio-gcp >= 0.2.2, < 1.0dev",
 }
 
 
diff --git a/testing/constraints-3.6.txt b/testing/constraints-3.6.txt
index 014e2b2a..c3e6ad74 100644
--- a/testing/constraints-3.6.txt
+++ b/testing/constraints-3.6.txt
@@ -11,6 +11,4 @@ google-auth==1.25.0
 requests==2.18.0
 packaging==14.3
 grpcio==1.33.2
-grpcio-gcp==0.2.2
-grpcio-gcp==0.2.2
 grpcio-status==1.33.2
diff --git a/testing/constraints-3.7.txt b/testing/constraints-3.7.txt
index e69de29b..c3e6ad74 100644
--- a/testing/constraints-3.7.txt
+++ b/testing/constraints-3.7.txt
@@ -0,0 +1,14 @@
+# This constraints file is used to check that lower bounds
+# are correct in setup.py
+# List *all* library dependencies and extras in this file.
+# Pin the version to the lower bound.
+#
+# e.g., if setup.py has "foo >= 1.14.0, < 2.0.0dev",
+# Then this file should have foo==1.14.0
+googleapis-common-protos==1.56.2
+protobuf==3.15.0
+google-auth==1.25.0
+requests==2.18.0
+packaging==14.3
+grpcio==1.33.2
+grpcio-status==1.33.2
diff --git a/tests/asyncio/test_grpc_helpers_async.py b/tests/asyncio/test_grpc_helpers_async.py
index 3681a40d..2d0a1bcd 100644
--- a/tests/asyncio/test_grpc_helpers_async.py
+++ b/tests/asyncio/test_grpc_helpers_async.py
@@ -565,11 +565,8 @@ def test_create_channel_with_credentials_file_and_default_scopes(
     grpc_secure_channel.assert_called_once_with(target, composite_creds)
 
 
-@pytest.mark.skipif(
-    grpc_helpers_async.HAS_GRPC_GCP, reason="grpc_gcp module not available"
-)
 @mock.patch("grpc.aio.secure_channel")
-def test_create_channel_without_grpc_gcp(grpc_secure_channel):
+def test_create_channel(grpc_secure_channel):
     target = "example.com:443"
     scopes = ["test_scope"]
 
diff --git a/tests/unit/test_grpc_helpers.py b/tests/unit/test_grpc_helpers.py
index ca969e48..649072f0 100644
--- a/tests/unit/test_grpc_helpers.py
+++ b/tests/unit/test_grpc_helpers.py
@@ -365,10 +365,7 @@ def test_create_channel_implicit(grpc_secure_channel, default, composite_creds_c
 
     default.assert_called_once_with(scopes=None, default_scopes=None)
 
-    if grpc_helpers.HAS_GRPC_GCP:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds, None)
-    else:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds)
+    grpc_secure_channel.assert_called_once_with(target, composite_creds)
 
 
 @mock.patch("google.auth.transport.grpc.AuthMetadataPlugin", autospec=True)
@@ -400,10 +397,7 @@ def test_create_channel_implicit_with_default_host(
         mock.sentinel.credentials, mock.sentinel.Request, default_host=default_host
     )
 
-    if grpc_helpers.HAS_GRPC_GCP:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds, None)
-    else:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds)
+    grpc_secure_channel.assert_called_once_with(target, composite_creds)
 
 
 @mock.patch("grpc.composite_channel_credentials")
@@ -426,10 +420,7 @@ def test_create_channel_implicit_with_ssl_creds(
 
     composite_creds_call.assert_called_once_with(ssl_creds, mock.ANY)
     composite_creds = composite_creds_call.return_value
-    if grpc_helpers.HAS_GRPC_GCP:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds, None)
-    else:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds)
+    grpc_secure_channel.assert_called_once_with(target, composite_creds)
 
 
 @mock.patch("grpc.composite_channel_credentials")
@@ -451,10 +442,7 @@ def test_create_channel_implicit_with_scopes(
 
     default.assert_called_once_with(scopes=["one", "two"], default_scopes=None)
 
-    if grpc_helpers.HAS_GRPC_GCP:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds, None)
-    else:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds)
+    grpc_secure_channel.assert_called_once_with(target, composite_creds)
 
 
 @mock.patch("grpc.composite_channel_credentials")
@@ -476,10 +464,7 @@ def test_create_channel_implicit_with_default_scopes(
 
     default.assert_called_once_with(scopes=None, default_scopes=["three", "four"])
 
-    if grpc_helpers.HAS_GRPC_GCP:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds, None)
-    else:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds)
+    grpc_secure_channel.assert_called_once_with(target, composite_creds)
 
 
 def test_create_channel_explicit_with_duplicate_credentials():
@@ -507,10 +492,7 @@ def test_create_channel_explicit(grpc_secure_channel, auth_creds, composite_cred
     )
 
     assert channel is grpc_secure_channel.return_value
-    if grpc_helpers.HAS_GRPC_GCP:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds, None)
-    else:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds)
+    grpc_secure_channel.assert_called_once_with(target, composite_creds)
 
 
 @mock.patch("grpc.composite_channel_credentials")
@@ -530,10 +512,7 @@ def test_create_channel_explicit_scoped(grpc_secure_channel, composite_creds_cal
     credentials.with_scopes.assert_called_once_with(scopes, default_scopes=None)
 
     assert channel is grpc_secure_channel.return_value
-    if grpc_helpers.HAS_GRPC_GCP:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds, None)
-    else:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds)
+    grpc_secure_channel.assert_called_once_with(target, composite_creds)
 
 
 @mock.patch("grpc.composite_channel_credentials")
@@ -557,10 +536,7 @@ def test_create_channel_explicit_default_scopes(
     )
 
     assert channel is grpc_secure_channel.return_value
-    if grpc_helpers.HAS_GRPC_GCP:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds, None)
-    else:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds)
+    grpc_secure_channel.assert_called_once_with(target, composite_creds)
 
 
 @mock.patch("grpc.composite_channel_credentials")
@@ -582,10 +558,7 @@ def test_create_channel_explicit_with_quota_project(
     credentials.with_quota_project.assert_called_once_with("project-foo")
 
     assert channel is grpc_secure_channel.return_value
-    if grpc_helpers.HAS_GRPC_GCP:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds, None)
-    else:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds)
+    grpc_secure_channel.assert_called_once_with(target, composite_creds)
 
 
 @mock.patch("grpc.composite_channel_credentials")
@@ -610,10 +583,7 @@ def test_create_channel_with_credentials_file(
     )
 
     assert channel is grpc_secure_channel.return_value
-    if grpc_helpers.HAS_GRPC_GCP:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds, None)
-    else:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds)
+    grpc_secure_channel.assert_called_once_with(target, composite_creds)
 
 
 @mock.patch("grpc.composite_channel_credentials")
@@ -641,10 +611,7 @@ def test_create_channel_with_credentials_file_and_scopes(
     )
 
     assert channel is grpc_secure_channel.return_value
-    if grpc_helpers.HAS_GRPC_GCP:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds, None)
-    else:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds)
+    grpc_secure_channel.assert_called_once_with(target, composite_creds)
 
 
 @mock.patch("grpc.composite_channel_credentials")
@@ -672,32 +639,11 @@ def test_create_channel_with_credentials_file_and_default_scopes(
     )
 
     assert channel is grpc_secure_channel.return_value
-    if grpc_helpers.HAS_GRPC_GCP:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds, None)
-    else:
-        grpc_secure_channel.assert_called_once_with(target, composite_creds)
+    grpc_secure_channel.assert_called_once_with(target, composite_creds)
 
 
-@pytest.mark.skipif(
-    not grpc_helpers.HAS_GRPC_GCP, reason="grpc_gcp module not available"
-)
-@mock.patch("grpc_gcp.secure_channel")
-def test_create_channel_with_grpc_gcp(grpc_gcp_secure_channel):
-    target = "example.com:443"
-    scopes = ["test_scope"]
-
-    credentials = mock.create_autospec(google.auth.credentials.Scoped, instance=True)
-    credentials.requires_scopes = True
-
-    grpc_helpers.create_channel(target, credentials=credentials, scopes=scopes)
-    grpc_gcp_secure_channel.assert_called()
-
-    credentials.with_scopes.assert_called_once_with(scopes, default_scopes=None)
-
-
-@pytest.mark.skipif(grpc_helpers.HAS_GRPC_GCP, reason="grpc_gcp module not available")
 @mock.patch("grpc.secure_channel")
-def test_create_channel_without_grpc_gcp(grpc_secure_channel):
+def test_create_channel(grpc_secure_channel):
     target = "example.com:443"
     scopes = ["test_scope"]