diff --git a/compiler/natives/src/internal/coverage/slicereader/slicereader.go b/compiler/natives/src/internal/coverage/slicereader/slicereader.go
new file mode 100644
index 000000000..4346d7c97
--- /dev/null
+++ b/compiler/natives/src/internal/coverage/slicereader/slicereader.go
@@ -0,0 +1,9 @@
+//go:build js
+// +build js
+
+package slicereader
+
+// Overwritten to avoid `unsafe.String`
+func toString(b []byte) string {
+	return string(b)
+}
diff --git a/compiler/natives/src/math/rand/rand.go b/compiler/natives/src/math/rand/rand.go
new file mode 100644
index 000000000..0dfb1b279
--- /dev/null
+++ b/compiler/natives/src/math/rand/rand.go
@@ -0,0 +1,9 @@
+//go:build js
+// +build js
+
+package rand
+
+import _ "unsafe"
+
+//go:linkname fastrand64 runtime.fastrand64
+func fastrand64() uint64
diff --git a/compiler/natives/src/net/http/client_test.go b/compiler/natives/src/net/http/client_test.go
index 302b800df..b3739fc09 100644
--- a/compiler/natives/src/net/http/client_test.go
+++ b/compiler/natives/src/net/http/client_test.go
@@ -6,14 +6,14 @@ import (
 	"testing"
 )
 
-func testClientTimeout(t *testing.T, h2 bool) {
+func testClientTimeout(t *testing.T, mode testMode) {
 	// The original test expects Client.Timeout error to be returned, but under
 	// GopherJS an "i/o timeout" error is frequently returned. Otherwise the test
 	// seems to be working correctly.
 	t.Skip("Flaky test under GopherJS.")
 }
 
-func testClientTimeout_Headers(t *testing.T, h2 bool) {
+func testClientTimeout_Headers(t *testing.T, mode testMode) {
 	// The original test expects Client.Timeout error to be returned, but under
 	// GopherJS an "i/o timeout" error is frequently returned. Otherwise the test
 	// seems to be working correctly.
diff --git a/compiler/natives/src/net/http/clientserver_test.go b/compiler/natives/src/net/http/clientserver_test.go
index 35b44dd4d..39f1a2d73 100644
--- a/compiler/natives/src/net/http/clientserver_test.go
+++ b/compiler/natives/src/net/http/clientserver_test.go
@@ -7,10 +7,10 @@ import (
 	"testing"
 )
 
-func testTransportGCRequest(t *testing.T, h2, body bool) {
+func testTransportGCRequest(t *testing.T, mode testMode, body bool) {
 	t.Skip("The test relies on runtime.SetFinalizer(), which is not supported by GopherJS.")
 }
 
-func testWriteHeaderAfterWrite(t *testing.T, h2, hijack bool) {
+func testWriteHeaderAfterWrite(t *testing.T, mode testMode, hijack bool) {
 	t.Skip("GopherJS source maps don't preserve original function names in stack traces, which this test relied on.")
 }
diff --git a/compiler/natives/src/strings/strings_test.go b/compiler/natives/src/strings/strings_test.go
index fb9a4a57a..3b0775e63 100644
--- a/compiler/natives/src/strings/strings_test.go
+++ b/compiler/natives/src/strings/strings_test.go
@@ -18,5 +18,9 @@ func TestCompareStrings(t *testing.T) {
 }
 
 func TestClone(t *testing.T) {
-	t.Skip("conversion to reflect.StringHeader is not supported in GopherJS")
+	t.Skip("conversion to unsafe.StringData is not supported in GopherJS")
+}
+
+func TestMap(t *testing.T) {
+	t.Skip("identity test uses unsafe.StringData is not supported in GopherJS")
 }
diff --git a/compiler/natives/src/syscall/syscall_js_wasm.go b/compiler/natives/src/syscall/syscall_js_wasm.go
index 5bcbdeed4..7ee92342e 100644
--- a/compiler/natives/src/syscall/syscall_js_wasm.go
+++ b/compiler/natives/src/syscall/syscall_js_wasm.go
@@ -22,6 +22,14 @@ func runtime_envs() []string {
 	return envs
 }
 
+func runtimeSetenv(k, v string) {
+	setenv_c(k, v)
+}
+
+func runtimeUnsetenv(k string) {
+	unsetenv_c(k)
+}
+
 func setenv_c(k, v string) {
 	process := js.Global().Get("process")
 	if process.IsUndefined() {