diff --git a/AK/NonnullOwnPtr.h b/AK/NonnullOwnPtr.h
index efb3fef7044..f1f07011a68 100644
--- a/AK/NonnullOwnPtr.h
+++ b/AK/NonnullOwnPtr.h
@@ -121,6 +121,9 @@ public:
     CALLABLE_WHEN(unconsumed)
     operator T*() { return m_ptr; }
 
+    operator bool() const = delete;
+    bool operator!() const = delete;
+
 private:
     void clear()
     {
diff --git a/AK/NonnullRefPtr.h b/AK/NonnullRefPtr.h
index 812457a01ad..90ad50ca751 100644
--- a/AK/NonnullRefPtr.h
+++ b/AK/NonnullRefPtr.h
@@ -221,6 +221,9 @@ public:
         return *m_ptr;
     }
 
+    operator bool() const = delete;
+    bool operator!() const = delete;
+
 private:
     NonnullRefPtr() = delete;