diff --git a/src/browser/Page.zig b/src/browser/Page.zig
index 48daeeb5..aab9b6f7 100644
--- a/src/browser/Page.zig
+++ b/src/browser/Page.zig
@@ -100,6 +100,7 @@ _script_manager: ScriptManager,
 // List of active MutationObservers
 _mutation_observers: std.ArrayList(*MutationObserver) = .{},
 _mutation_delivery_scheduled: bool = false,
+_mutation_delivery_depth: u32 = 0,
 
 // List of active IntersectionObservers
 _intersection_observers: std.ArrayList(*IntersectionObserver) = .{},
@@ -244,6 +245,7 @@ fn reset(self: *Page, comptime initializing: bool) !void {
 
     self._mutation_observers = .{};
     self._mutation_delivery_scheduled = false;
+    self._mutation_delivery_depth = 0;
     self._intersection_observers = .{};
     self._intersection_delivery_scheduled = false;
     self._customized_builtin_definitions = .{};
@@ -849,6 +851,18 @@ pub fn deliverMutations(self: *Page) void {
     }
     self._mutation_delivery_scheduled = false;
 
+    self._mutation_delivery_depth += 1;
+    defer if (!self._mutation_delivery_scheduled) {
+        // reset the depth once nothing is left to be scheduled
+        self._mutation_delivery_depth = 0;
+    };
+
+    if (self._mutation_delivery_depth > 100) {
+        log.err(.page, "page.MutationLimit", .{});
+        self._mutation_delivery_depth = 0;
+        return;
+    }
+
     // Iterate backwards to handle observers that disconnect during their callback
     var i = self._mutation_observers.items.len;
     while (i > 0) {
diff --git a/src/browser/tests/legacy/dom/mutation_observer.html b/src/browser/tests/legacy/dom/mutation_observer.html
deleted file mode 100644
index f67cb924..00000000
--- a/src/browser/tests/legacy/dom/mutation_observer.html
+++ /dev/null
@@ -1,76 +0,0 @@
-<!DOCTYPE html>
-<div></div>
-<div id=d1><p id=p1> And</p></div>
-<div id=d2><p id=p2> And</p></div>
-<div id=d3><p id=p3> And</p></div>
-
-<script src="../testing.js"></script>
-<script id=mutationObserver>
-  // doesn't crash, yay.
-  new MutationObserver(() => {}).observe(document, { childList: true });
-
-  var nb = 0;
-  var mrs;
-  let cb_this1;
-  let mu1 = new MutationObserver(function(mu) {
-     mrs = mu;
-     nb++;
-     cb_this1 = this;
-  });
-  mu1.observe(document.firstElementChild, { attributes: true, attributeOldValue: true });
-  document.firstElementChild.setAttribute("foo", "bar");
-  document.firstElementChild.firstChild.setAttribute("foo", "bar");
-
-  testing.eventually(() => {
-    testing.expectEqual(1, nb);
-    testing.expectEqual(cb_this1, mu1);
-    testing.expectEqual('attributes', mrs[0].type);
-    testing.expectEqual(document.firstElementChild, mrs[0].target);
-    testing.expectEqual('bar', mrs[0].target.getAttribute('foo'));
-    testing.expectEqual('foo', mrs[0].attributeName);
-    testing.expectEqual(null, mrs[0].oldValue);
-  });
-
-  var nb2 = 0;
-  var mrs2;
-  var node1 = $('#p1').firstChild;
-  let mu2 = new MutationObserver((mu) => {
-      mrs2 = mu;
-      nb2++;
-      cb_this2 = this;
-  })
-  mu2.observe(node1, { characterData: true, characterDataOldValue: true });
-  node1.data = "foo";
-
-  testing.eventually(() => {
-    testing.expectEqual(1, nb2);
-    testing.expectEqual(window, cb_this2);
-    testing.expectEqual('characterData', mrs2[0].type);
-    testing.expectEqual(node1, mrs2[0].target);
-    testing.expectEqual('foo', mrs2[0].target.data);
-    testing.expectEqual(' And', mrs2[0].oldValue);
-  });
-</script>
-
-<script id=callback>
-  // tests that mutation observers that have a callback which trigger the
-  // mutation observer don't crash.
-  // https://github.com/lightpanda-io/browser/issues/550
-  var node2 = $("#p2");
-  new MutationObserver(() => {
-      node2.innerText = 'a';
-  }).observe($('#d2'), { subtree:true, childList:true });
-  node2.innerText = "2";
-  testing.eventually(() => testing.expectEqual('a', node2.innerText));
-
-  var node3 = $("#p3");
-  var attrWatch = 0;
-  new MutationObserver(() => {
-      attrWatch++;
-  }).observe($('#d3'), { attributeFilter: ["name"], subtree: true });
-  node3.setAttribute("id", "1");
-
-  testing.expectEqual(0, attrWatch);
-  node3.setAttribute('name', 'other');
-  testing.eventually(() => testing.expectEqual(1, attrWatch));
-</script>
