diff --git a/1.2.1/_static/mpl.css b/1.2.1/_static/mpl.css
index 7aa01b73165..a06115eab90 100644
--- a/1.2.1/_static/mpl.css
+++ b/1.2.1/_static/mpl.css
@@ -505,3 +505,28 @@ ul.search li div.context {
 ul.keywordmatches li.goodmatch a {
     font-weight: bold;
 }
+
+/* "Go to released version" message. */
+#unreleased-message {
+  background: #d62728;
+  box-sizing: border-box;
+  color: #fff;
+  font-weight: bold;
+  left: 0;
+  min-height: 3em;
+  padding: 0.7em;
+  position: fixed;
+  top: 0;
+  width: 100%;
+  z-index: 10000;
+}
+
+#unreleased-message + div {
+  margin-top: 3em;
+}
+
+#unreleased-message a {
+  color: #fff;
+  text-decoration:underline;
+
+}
diff --git a/1.3.0/_static/mpl.css b/1.3.0/_static/mpl.css
index bd174f670d4..6568807df7f 100644
--- a/1.3.0/_static/mpl.css
+++ b/1.3.0/_static/mpl.css
@@ -566,3 +566,27 @@ table.docutils td {
   width: 30em;
 }
 
+/* "Go to released version" message. */
+#unreleased-message {
+  background: #d62728;
+  box-sizing: border-box;
+  color: #fff;
+  font-weight: bold;
+  left: 0;
+  min-height: 3em;
+  padding: 0.7em;
+  position: fixed;
+  top: 0;
+  width: 100%;
+  z-index: 10000;
+}
+
+#unreleased-message + div {
+  margin-top: 3em;
+}
+
+#unreleased-message a {
+  color: #fff;
+  text-decoration:underline;
+
+}
diff --git a/1.3.1/_static/mpl.css b/1.3.1/_static/mpl.css
index bd174f670d4..ddc6982bc51 100644
--- a/1.3.1/_static/mpl.css
+++ b/1.3.1/_static/mpl.css
@@ -566,3 +566,27 @@ table.docutils td {
   width: 30em;
 }
 
+
+/* "Go to released version" message. */
+#unreleased-message {
+  background: #d62728;
+  box-sizing: border-box;
+  color: #fff;
+  font-weight: bold;
+  left: 0;
+  min-height: 3em;
+  padding: 0.7em;
+  position: fixed;
+  top: 0;
+  width: 100%;
+  z-index: 10000;
+}
+
+#unreleased-message + div {
+  margin-top: 3em;
+}
+
+#unreleased-message a {
+  color: #fff;
+  text-decoration:underline;
+}
diff --git a/1.4.0/_static/mpl.css b/1.4.0/_static/mpl.css
index 545997d29c8..692ddf3c00f 100644
--- a/1.4.0/_static/mpl.css
+++ b/1.4.0/_static/mpl.css
@@ -650,3 +650,27 @@ figcaption {
 }
 
 
+
+/* "Go to released version" message. */
+#unreleased-message {
+  background: #d62728;
+  box-sizing: border-box;
+  color: #fff;
+  font-weight: bold;
+  left: 0;
+  min-height: 3em;
+  padding: 0.7em;
+  position: fixed;
+  top: 0;
+  width: 100%;
+  z-index: 10000;
+}
+
+#unreleased-message + div {
+  margin-top: 3em;
+}
+
+#unreleased-message a {
+  color: #fff;
+  text-decoration:underline;
+}
diff --git a/1.4.1/_static/mpl.css b/1.4.1/_static/mpl.css
index 545997d29c8..692ddf3c00f 100644
--- a/1.4.1/_static/mpl.css
+++ b/1.4.1/_static/mpl.css
@@ -650,3 +650,27 @@ figcaption {
 }
 
 
+
+/* "Go to released version" message. */
+#unreleased-message {
+  background: #d62728;
+  box-sizing: border-box;
+  color: #fff;
+  font-weight: bold;
+  left: 0;
+  min-height: 3em;
+  padding: 0.7em;
+  position: fixed;
+  top: 0;
+  width: 100%;
+  z-index: 10000;
+}
+
+#unreleased-message + div {
+  margin-top: 3em;
+}
+
+#unreleased-message a {
+  color: #fff;
+  text-decoration:underline;
+}
diff --git a/1.4.2/_static/mpl.css b/1.4.2/_static/mpl.css
index 545997d29c8..692ddf3c00f 100644
--- a/1.4.2/_static/mpl.css
+++ b/1.4.2/_static/mpl.css
@@ -650,3 +650,27 @@ figcaption {
 }
 
 
+
+/* "Go to released version" message. */
+#unreleased-message {
+  background: #d62728;
+  box-sizing: border-box;
+  color: #fff;
+  font-weight: bold;
+  left: 0;
+  min-height: 3em;
+  padding: 0.7em;
+  position: fixed;
+  top: 0;
+  width: 100%;
+  z-index: 10000;
+}
+
+#unreleased-message + div {
+  margin-top: 3em;
+}
+
+#unreleased-message a {
+  color: #fff;
+  text-decoration:underline;
+}
diff --git a/1.4.3/_static/mpl.css b/1.4.3/_static/mpl.css
index 545997d29c8..692ddf3c00f 100644
--- a/1.4.3/_static/mpl.css
+++ b/1.4.3/_static/mpl.css
@@ -650,3 +650,27 @@ figcaption {
 }
 
 
+
+/* "Go to released version" message. */
+#unreleased-message {
+  background: #d62728;
+  box-sizing: border-box;
+  color: #fff;
+  font-weight: bold;
+  left: 0;
+  min-height: 3em;
+  padding: 0.7em;
+  position: fixed;
+  top: 0;
+  width: 100%;
+  z-index: 10000;
+}
+
+#unreleased-message + div {
+  margin-top: 3em;
+}
+
+#unreleased-message a {
+  color: #fff;
+  text-decoration:underline;
+}
diff --git a/1.5.0/_static/mpl.css b/1.5.0/_static/mpl.css
index 545997d29c8..692ddf3c00f 100644
--- a/1.5.0/_static/mpl.css
+++ b/1.5.0/_static/mpl.css
@@ -650,3 +650,27 @@ figcaption {
 }
 
 
+
+/* "Go to released version" message. */
+#unreleased-message {
+  background: #d62728;
+  box-sizing: border-box;
+  color: #fff;
+  font-weight: bold;
+  left: 0;
+  min-height: 3em;
+  padding: 0.7em;
+  position: fixed;
+  top: 0;
+  width: 100%;
+  z-index: 10000;
+}
+
+#unreleased-message + div {
+  margin-top: 3em;
+}
+
+#unreleased-message a {
+  color: #fff;
+  text-decoration:underline;
+}
diff --git a/1.5.1/_static/mpl.css b/1.5.1/_static/mpl.css
index 66cd21fe64f..0204e7c6a55 100644
--- a/1.5.1/_static/mpl.css
+++ b/1.5.1/_static/mpl.css
@@ -682,3 +682,27 @@ figcaption {
     background: #003c63;
     outline-color: #003c63;
 }
+
+/* "Go to released version" message. */
+#unreleased-message {
+  background: #d62728;
+  box-sizing: border-box;
+  color: #fff;
+  font-weight: bold;
+  left: 0;
+  min-height: 3em;
+  padding: 0.7em;
+  position: fixed;
+  top: 0;
+  width: 100%;
+  z-index: 10000;
+}
+
+#unreleased-message + div {
+  margin-top: 3em;
+}
+
+#unreleased-message a {
+  color: #fff;
+  text-decoration:underline;
+}
diff --git a/1.5.3/_static/mpl.css b/1.5.3/_static/mpl.css
index 66cd21fe64f..0204e7c6a55 100644
--- a/1.5.3/_static/mpl.css
+++ b/1.5.3/_static/mpl.css
@@ -682,3 +682,27 @@ figcaption {
     background: #003c63;
     outline-color: #003c63;
 }
+
+/* "Go to released version" message. */
+#unreleased-message {
+  background: #d62728;
+  box-sizing: border-box;
+  color: #fff;
+  font-weight: bold;
+  left: 0;
+  min-height: 3em;
+  padding: 0.7em;
+  position: fixed;
+  top: 0;
+  width: 100%;
+  z-index: 10000;
+}
+
+#unreleased-message + div {
+  margin-top: 3em;
+}
+
+#unreleased-message a {
+  color: #fff;
+  text-decoration:underline;
+}
diff --git a/2.0.0/_static/mpl.css b/2.0.0/_static/mpl.css
index 161a99edbc1..441edd24907 100644
--- a/2.0.0/_static/mpl.css
+++ b/2.0.0/_static/mpl.css
@@ -786,3 +786,27 @@ div.responsive_subfig img {
     }
 
 }
+
+/* "Go to released version" message. */
+#unreleased-message {
+  background: #d62728;
+  box-sizing: border-box;
+  color: #fff;
+  font-weight: bold;
+  left: 0;
+  min-height: 3em;
+  padding: 0.7em;
+  position: fixed;
+  top: 0;
+  width: 100%;
+  z-index: 10000;
+}
+
+#unreleased-message + div {
+  margin-top: 3em;
+}
+
+#unreleased-message a {
+  color: #fff;
+  text-decoration:underline;
+}
diff --git a/2.0.1/_static/mpl.css b/2.0.1/_static/mpl.css
index 9adea6173b4..a6e7b614982 100644
--- a/2.0.1/_static/mpl.css
+++ b/2.0.1/_static/mpl.css
@@ -787,3 +787,27 @@ div.responsive_subfig img {
     }
 
 }
+
+/* "Go to released version" message. */
+#unreleased-message {
+  background: #d62728;
+  box-sizing: border-box;
+  color: #fff;
+  font-weight: bold;
+  left: 0;
+  min-height: 3em;
+  padding: 0.7em;
+  position: fixed;
+  top: 0;
+  width: 100%;
+  z-index: 10000;
+}
+
+#unreleased-message + div {
+  margin-top: 3em;
+}
+
+#unreleased-message a {
+  color: #fff;
+  text-decoration:underline;
+}
diff --git a/2.0.2/_static/mpl.css b/2.0.2/_static/mpl.css
index 9adea6173b4..a6e7b614982 100644
--- a/2.0.2/_static/mpl.css
+++ b/2.0.2/_static/mpl.css
@@ -787,3 +787,27 @@ div.responsive_subfig img {
     }
 
 }
+
+/* "Go to released version" message. */
+#unreleased-message {
+  background: #d62728;
+  box-sizing: border-box;
+  color: #fff;
+  font-weight: bold;
+  left: 0;
+  min-height: 3em;
+  padding: 0.7em;
+  position: fixed;
+  top: 0;
+  width: 100%;
+  z-index: 10000;
+}
+
+#unreleased-message + div {
+  margin-top: 3em;
+}
+
+#unreleased-message a {
+  color: #fff;
+  text-decoration:underline;
+}
diff --git a/_websiteutils/fixcss.py b/_websiteutils/fixcss.py
new file mode 100644
index 00000000000..2fd32d5d6f7
--- /dev/null
+++ b/_websiteutils/fixcss.py
@@ -0,0 +1,56 @@
+import pathlib
+import tempfile
+import shutil
+
+tocheck =  [
+    pathlib.Path(f"{major}.{minor}.{micro}")
+    for major in range(2, -1, -1)
+    for minor in range(6, -1, -1)
+    for micro in range(6, -1, -1)
+]
+
+
+to_add = b"""
+/* "Go to released version" message. */
+#unreleased-message {
+  background: #d62728;
+  box-sizing: border-box;
+  color: #fff;
+  font-weight: bold;
+  left: 0;
+  min-height: 3em;
+  padding: 0.7em;
+  position: fixed;
+  top: 0;
+  width: 100%;
+  z-index: 10000;
+}
+
+#unreleased-message + div {
+  margin-top: 3em;
+}
+
+#unreleased-message a {
+  color: #fff;
+  text-decoration:underline;
+}
+"""
+
+for d in tocheck:
+
+    fname = pathlib.Path(d, '_static', 'mpl.css')
+    if fname.is_file():
+        print(f'checking {fname}')
+        with open(fname) as f:
+            if not "#unreleased-message" in f.read():
+                doit = True
+            else:
+                doit = False
+        if doit:
+            print(f'doing {d}')
+            with tempfile.NamedTemporaryFile(delete=False) as fout:
+                with open(fname, 'rb') as f:
+                    fout.write(f.read())
+                fout.write(to_add)
+            print(f.name)
+            shutil.move(fout.name, f.name)