diff --git a/moli-core/tests/history_child_joint.rs b/moli-core/tests/history_child_joint.rs
new file mode 100644
index 0000000000..b92f820b85
--- /dev/null
+++ b/moli-core/tests/history_child_joint.rs
@@ -0,0 +1,113 @@
+use anyhow::Result;
+use moli_core::runtime::{Browser, BrowserConfig};
+use moli_test_support::FixtureServer;
+use tokio::time::Duration;
+use url::Url;
+
+fn markup_url(server: &FixtureServer, markup: &str) -> String {
+    let mut url = Url::parse(&server.url("/compat/child-dynamic-markup-document")).unwrap();
+    url.query_pairs_mut().append_pair("markup", markup);
+    url.into()
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn top_level_back_skips_replaced_initial_child_entries() -> Result<()> {
+    let server = FixtureServer::spawn().await?;
+    for (replace, blank_predecessor) in [(false, false), (true, false), (true, true)] {
+        let browser = Browser::new(BrowserConfig::default())?;
+        let destination = server.url("/static?replacement");
+        let source = if replace {
+            markup_url(
+                &server,
+                &format!(
+                    "<!doctype html><script>location.replace({});</script>",
+                    serde_json::to_string(&destination)?
+                ),
+            )
+        } else {
+            destination.clone()
+        };
+        let previous = if blank_predecessor {
+            "about:blank".to_owned()
+        } else {
+            server.url("/static?sentinel-start")
+        };
+        let markup = format!(
+            r#"<!doctype html><body><script>
+              function loaded(frame, target) {{
+                return new Promise(resolve => {{
+                  const listener = () => {{
+                    if (frame.contentWindow.location.href === new URL(target, location.href).href) {{
+                      frame.removeEventListener('load', listener);
+                      setTimeout(resolve, 0);
+                    }}
+                  }};
+                  frame.addEventListener('load', listener);
+                }});
+              }}
+              window.finished = (async () => {{
+                const sentinel = document.createElement('iframe');
+                let pending = loaded(sentinel, '/static?sentinel-start');
+                sentinel.src = '/static?sentinel-start';
+                document.body.append(sentinel);
+                await pending;
+                const previous = {};
+                if (previous === 'about:blank') {{
+                  pending = loaded(sentinel, previous);
+                  sentinel.src = previous;
+                  await pending;
+                }}
+                pending = loaded(sentinel, '/static?sentinel-end');
+                sentinel.src = '/static?sentinel-end';
+                await pending;
+                const initialLength = history.length;
+                const other = document.createElement('iframe');
+                pending = loaded(other, {});
+                other.src = {};
+                document.body.append(other);
+                await pending;
+                pending = loaded(sentinel, previous);
+                history.back();
+                await pending;
+                return {{
+                  unchangedLength: history.length === initialLength,
+                  sentinelURL: sentinel.contentWindow.location.href,
+                  otherURL: other.contentWindow.location.href,
+                  sentinelIndex: sentinel.contentWindow.navigation.currentEntry.index,
+                  otherIndex: other.contentWindow.navigation.currentEntry.index
+                }};
+              }})();
+            </script>"#,
+            serde_json::to_string(&previous)?,
+            serde_json::to_string(&destination)?,
+            serde_json::to_string(&source)?.replace("</script>", "<\\/script>")
+        );
+        let result = tokio::time::timeout(Duration::from_secs(10), async {
+            let mut page = browser.fetch(&markup_url(&server, &markup)).await?;
+            page.evaluate_runtime_expression_with_await_async(
+                "finished.then(value => JSON.stringify(value))",
+                true,
+            )
+            .await
+        })
+        .await??;
+        let result: serde_json::Value = serde_json::from_str(
+            result["value"]
+                .as_str()
+                .expect("joint history traversal result"),
+        )?;
+        assert_eq!(
+            result,
+            serde_json::json!({
+                "unchangedLength": true,
+                "sentinelURL": previous,
+                "otherURL": destination,
+                "sentinelIndex": u32::from(blank_predecessor),
+                "otherIndex": 0
+            }),
+            "replace={replace}, blank_predecessor={blank_predecessor}"
+        );
+    }
+    server.shutdown().await;
+    Ok(())
+}