diff --git a/changelog.d/9913-test-mock-prototype.md b/changelog.d/9913-test-mock-prototype.md
new file mode 100644
index 0000000000..04063d419e
--- /dev/null
+++ b/changelog.d/9913-test-mock-prototype.md
@@ -0,0 +1 @@
+`node:test`'s `mock.method()` now replaces declared class prototype methods for instance dispatch and restores their original behavior, while recording calls and receiver identity like Node.
diff --git a/crates/perry-runtime/src/node_submodules/test.rs b/crates/perry-runtime/src/node_submodules/test.rs
index cb70c0b994..15acb0c498 100644
--- a/crates/perry-runtime/src/node_submodules/test.rs
+++ b/crates/perry-runtime/src/node_submodules/test.rs
@@ -367,6 +367,22 @@ fn set_property_value(target: f64, property: &str, value: f64) {
     }
 }
 
+fn set_method_property_value(target: f64, property: &str, value: f64) {
+    let raw = raw_ptr_from_value(target);
+    if let Some(class_id) = crate::object::class_id_for_decl_prototype_object(raw) {
+        unsafe {
+            crate::object::js_register_prototype_method(
+                class_id,
+                property.as_ptr(),
+                property.len(),
+                value,
+            );
+        }
+    } else {
+        set_property_value(target, property, value);
+    }
+}
+
 fn get_property_value(target: f64, property: &str) -> f64 {
     let raw = raw_ptr_from_value(target);
     if raw >= 0x10000 && crate::closure::is_closure_ptr(raw) {
@@ -691,7 +707,7 @@ fn restore_mock_state(id: i64) {
             target,
             property,
             original,
-        }) => set_property_value(target, &property, original),
+        }) => set_method_property_value(target, &property, original),
         Some(MockRestoreTarget::ObjectAccessor {
             target,
             property,
@@ -1036,7 +1052,7 @@ extern "C" fn mock_method_thunk(
             original,
         },
     );
-    set_property_value(target.get_nanbox_f64(), &property_name, function);
+    set_method_property_value(target.get_nanbox_f64(), &property_name, function);
     function
 }
 
diff --git a/test-parity/node-suite/test/mock-fn/prototype-method.ts b/test-parity/node-suite/test/mock-fn/prototype-method.ts
index c6e2756b69..bcf7138aeb 100644
--- a/test-parity/node-suite/test/mock-fn/prototype-method.ts
+++ b/test-parity/node-suite/test/mock-fn/prototype-method.ts
@@ -1,7 +1,10 @@
 import { mock } from "node:test";
 
 class Counter {
-  constructor(public value: number) {}
+  value: number;
+  constructor(value: number) {
+    this.value = value;
+  }
   read() {
     return this.value;
   }