diff --git a/.netlify/build.sh b/.netlify/build.sh
index 215ee8c8..dc341d5a 100755
--- a/.netlify/build.sh
+++ b/.netlify/build.sh
@@ -60,9 +60,7 @@ echo "<meta http-equiv=refresh content=0;url=pyo3/>" > netlify_build/main/doc/in
 
 ## Build internal docs
 
-echo "<div class='internal-banner' style='position:fixed; z-index: 99999; color:red;border:3px solid red;margin-left: auto; margin-right: auto; width: 430px;left:0;right: 0;'><div style='display: flex; align-items: center; justify-content: center;'> ⚠️ Internal Docs ⚠️ Not Public API 👉 <a href='https://pyo3.rs/main/doc/pyo3/index.html' style='color:red;text-decoration:underline;'>Official Docs Here</a></div></div>" > netlify_build/banner.html
-RUSTDOCFLAGS="--html-before-content netlify_build/banner.html" nox -s docs -- nightly internal
-rm netlify_build/banner.html
+nox -s docs -- nightly internal
 
 mkdir -p netlify_build/internal
 mv target/doc netlify_build/internal/
diff --git a/.netlify/internal_banner.html b/.netlify/internal_banner.html
new file mode 100644
index 00000000..6f1024e4
--- /dev/null
+++ b/.netlify/internal_banner.html
@@ -0,0 +1,47 @@
+<div id='pyo3-internal-banner'>
+    <div style="white-space: nowrap;">
+        ⚠️ Internal Docs ⚠️ Not Public API 👉
+        <a href='https://pyo3.rs/main/doc/pyo3/index.html' style='color:red;text-decoration:underline;'>
+            Official Docs Here
+        </a>
+    </div>
+    <style id="pyo3-noscript-style">
+        body {
+            padding-top: 2em;
+        }
+    </style>
+    <style>
+        #pyo3-internal-banner {
+            position: fixed;
+            display: flex;
+            align-items: center;
+            justify-content:
+                center;
+            z-index: 99999;
+            color: red;
+            left: 0;
+            right: 0;
+            top: 0;
+            height: 2em;
+            border: 3px solid red;
+            width: 100%;
+            overflow-x: hidden;
+            background-color: var(--target-background-color);
+        }
+
+        @media (max-width: 700px) {
+            #pyo3-internal-banner {
+                top: 50px;
+                margin-bottom: 10px;
+            }
+        }
+    </style>
+</div>
+<script>
+    // when javascript is active, splice the banner into a "sticky" location
+    // inside the doc body for best appearance
+    banner = document.getElementById("pyo3-internal-banner")
+    banner.style.position = "sticky"
+    document.getElementsByTagName("main")[0].prepend(banner)
+    document.getElementById("pyo3-noscript-style").remove()
+</script>
diff --git a/noxfile.py b/noxfile.py
index 4e1c9347..8ee15a82 100644
--- a/noxfile.py
+++ b/noxfile.py
@@ -305,6 +305,7 @@ def docs(session: nox.Session) -> None:
     if "nightly" in session.posargs and "internal" in session.posargs:
         rustdoc_flags.append("--Z unstable-options")
         rustdoc_flags.append("--document-hidden-items")
+        rustdoc_flags.extend(("--html-after-content", ".netlify/internal_banner.html"))
         cargo_flags.append("--document-private-items")
     else:
         cargo_flags.extend(["--exclude=pyo3-macros", "--exclude=pyo3-macros-backend"])