diff --git a/inputfiles/patches/intersection-observer.kdl b/inputfiles/patches/intersection-observer.kdl
index 8bba2a34b..5b31bb855 100644
--- a/inputfiles/patches/intersection-observer.kdl
+++ b/inputfiles/patches/intersection-observer.kdl
@@ -1,4 +1,7 @@
 removals {
+  interface IntersectionObserverEntry {
+    constructor signatureIndex=0 // WebKit-only as of 2025-12
+  }
   dictionary IntersectionObserverInit {
     member delay           // Blink only as of 2025-12
     member trackVisibility // Blink only as of 2025-12
diff --git a/inputfiles/removedTypes.jsonc b/inputfiles/removedTypes.jsonc
index 66e382e56..46d5895a4 100644
--- a/inputfiles/removedTypes.jsonc
+++ b/inputfiles/removedTypes.jsonc
@@ -36,9 +36,6 @@
                     }
                 }
             },
-            "IntersectionObserverEntry": {
-                "constructor": null // WebKit-only as of 2024-07
-            },
             "OffscreenCanvasRenderingContext2D": {
                 "implements": ["CanvasSettings"] // Blink only as of 2025-01
             },
diff --git a/src/build/patches.ts b/src/build/patches.ts
index a2515c73f..04e8e2aca 100644
--- a/src/build/patches.ts
+++ b/src/build/patches.ts
@@ -248,8 +248,8 @@ function handleMixinAndInterfaces(
   return {
     name,
     ...optionalNestedMember("events", event, { event }),
-    properties: { property },
-    methods: { method },
+    ...optionalNestedMember("properties", property, { property }),
+    ...optionalNestedMember("methods", method, { method }),
     ...optionalMember("extends", "string", node.properties?.extends),
     ...optionalMember("overrideThis", "string", node.properties?.overrideThis),
     ...optionalMember("forward", "string", node.properties?.forward),
@@ -357,7 +357,7 @@ function handleMethodAndConstructor(
   const signatureIndex = child.properties?.signatureIndex;
   const type = handleTyped(typeNodes, child.properties?.returns);
 
-  let signature: OverridableMethod["signature"] = [];
+  let signature: OverridableMethod["signature"] | undefined = undefined;
   if (type || params.length > 0) {
     // Determine the actual signature object
     const signatureObj: DeepPartial<Signature> = {