diff --git a/js/extensions/extension.js b/js/extensions/extension.js
index a0d3f049d..c6a05f08b 100644
--- a/js/extensions/extension.js
+++ b/js/extensions/extension.js
@@ -1,3 +1,5 @@
+const Gi = imports._gi;
+
 import {ExtensionBase, GettextWrapper} from './sharedInternals.js';
 
 const {extensionManager} = imports.ui.main;
@@ -48,7 +50,7 @@ export class InjectionManager {
      */
     overrideMethod(prototype, methodName, createOverrideFunc) {
         const originalMethod = this._saveMethod(prototype, methodName);
-        prototype[methodName] = createOverrideFunc(originalMethod);
+        this._installMethod(prototype, methodName, createOverrideFunc(originalMethod));
     }
 
     /**
@@ -66,7 +68,7 @@ export class InjectionManager {
         if (originalMethod === undefined)
             delete prototype[methodName];
         else
-            prototype[methodName] = originalMethod;
+            this._installMethod(prototype, methodName, originalMethod);
 
         savedProtoMethods.delete(methodName);
         if (savedProtoMethods.size === 0)
@@ -96,4 +98,13 @@ export class InjectionManager {
         savedProtoMethods.set(methodName, originalMethod);
         return originalMethod;
     }
+
+    _installMethod(prototype, methodName, method) {
+        if (methodName.startsWith('vfunc_')) {
+            const giPrototype = prototype[Gi.gobject_prototype_symbol];
+            giPrototype[Gi.hook_up_vfunc_symbol](methodName.slice(6), method);
+        } else {
+            prototype[methodName] = method;
+        }
+    }
 }
diff --git a/tests/unit/injectionManager.js b/tests/unit/injectionManager.js
index 6de509441..e727f35e9 100644
--- a/tests/unit/injectionManager.js
+++ b/tests/unit/injectionManager.js
@@ -1,5 +1,7 @@
 const JsUnit = imports.jsUnit;
 
+import GObject from 'gi://GObject';
+
 import '../../js/ui/environment.js';
 
 import {InjectionManager} from '../../js/extensions/extension.js';
@@ -16,6 +18,23 @@ class Object1 {
     }
 }
 
+class GObject1 extends GObject.Object {
+    static [GObject.properties] = {
+        'plonked': GObject.ParamSpec.boolean(
+            'plonked', '', '',
+            GObject.ParamFlags.READWRITE,
+            false),
+    };
+
+    static {
+        GObject.registerClass(this);
+    }
+
+    plonk() {
+        this.set_property('plonked', true);
+    }
+}
+
 /**
  * @param {object} object to modify
  */
@@ -91,3 +110,28 @@ JsUnit.assertEquals(obj.getNumber(), 42);
 JsUnit.assertEquals(obj.getCount(), obj.count);
 JsUnit.assert(obj.count > 0);
 JsUnit.assertRaises(() => obj.getOtherNumber());
+
+// GObject injections
+const gobj = new GObject1();
+let vfuncCalled;
+
+injectionManager.overrideMethod(
+    GObject1.prototype, 'vfunc_set_property', originalMethod => {
+        return function (...args) {
+            // eslint-disable-next-line no-invalid-this
+            originalMethod.apply(this, args);
+            vfuncCalled = true;
+        };
+    });
+
+// gobj is now modified
+vfuncCalled = false;
+gobj.plonk();
+JsUnit.assertTrue(vfuncCalled);
+
+injectionManager.clear();
+
+// gobj is unmodified again
+vfuncCalled = false;
+gobj.plonk();
+JsUnit.assertFalse(vfuncCalled);