diff --git a/AK/NonnullOwnPtr.h b/AK/NonnullOwnPtr.h
index cd4a8624609..1553a9c562f 100644
--- a/AK/NonnullOwnPtr.h
+++ b/AK/NonnullOwnPtr.h
@@ -98,17 +98,26 @@ public:
         return exchange(m_ptr, nullptr);
     }
 
-    T* ptr() { return m_ptr; }
-    const T* ptr() const { return m_ptr; }
+    ALWAYS_INLINE RETURNS_NONNULL T* ptr()
+    {
+        VERIFY(m_ptr);
+        return m_ptr;
+    }
 
-    T* operator->() { return m_ptr; }
-    const T* operator->() const { return m_ptr; }
+    ALWAYS_INLINE RETURNS_NONNULL const T* ptr() const
+    {
+        VERIFY(m_ptr);
+        return m_ptr;
+    }
 
-    T& operator*() { return *m_ptr; }
-    const T& operator*() const { return *m_ptr; }
+    ALWAYS_INLINE RETURNS_NONNULL T* operator->() { return ptr(); }
+    ALWAYS_INLINE RETURNS_NONNULL const T* operator->() const { return ptr(); }
 
-    operator const T*() const { return m_ptr; }
-    operator T*() { return m_ptr; }
+    ALWAYS_INLINE T& operator*() { return *ptr(); }
+    ALWAYS_INLINE const T& operator*() const { return *ptr(); }
+
+    ALWAYS_INLINE RETURNS_NONNULL operator const T*() const { return ptr(); }
+    ALWAYS_INLINE RETURNS_NONNULL operator T*() { return ptr(); }
 
     operator bool() const = delete;
     bool operator!() const = delete;
diff --git a/AK/NonnullRefPtr.h b/AK/NonnullRefPtr.h
index 22936a2dfc4..b65f044ae91 100644
--- a/AK/NonnullRefPtr.h
+++ b/AK/NonnullRefPtr.h
@@ -156,20 +156,20 @@ public:
         return *ptr;
     }
 
-    ALWAYS_INLINE T* ptr()
+    ALWAYS_INLINE RETURNS_NONNULL T* ptr()
     {
         return as_nonnull_ptr();
     }
-    ALWAYS_INLINE const T* ptr() const
+    ALWAYS_INLINE RETURNS_NONNULL const T* ptr() const
     {
         return as_nonnull_ptr();
     }
 
-    ALWAYS_INLINE T* operator->()
+    ALWAYS_INLINE RETURNS_NONNULL T* operator->()
     {
         return as_nonnull_ptr();
     }
-    ALWAYS_INLINE const T* operator->() const
+    ALWAYS_INLINE RETURNS_NONNULL const T* operator->() const
     {
         return as_nonnull_ptr();
     }
@@ -183,11 +183,11 @@ public:
         return *as_nonnull_ptr();
     }
 
-    ALWAYS_INLINE operator T*()
+    ALWAYS_INLINE RETURNS_NONNULL operator T*()
     {
         return as_nonnull_ptr();
     }
-    ALWAYS_INLINE operator const T*() const
+    ALWAYS_INLINE RETURNS_NONNULL operator const T*() const
     {
         return as_nonnull_ptr();
     }
@@ -232,7 +232,7 @@ private:
         return (T*)(m_bits.load(AK::MemoryOrder::memory_order_relaxed) & ~(FlatPtr)1);
     }
 
-    ALWAYS_INLINE T* as_nonnull_ptr() const
+    ALWAYS_INLINE RETURNS_NONNULL T* as_nonnull_ptr() const
     {
         T* ptr = (T*)(m_bits.load(AK::MemoryOrder::memory_order_relaxed) & ~(FlatPtr)1);
         VERIFY(ptr);
diff --git a/AK/Platform.h b/AK/Platform.h
index 54264348b4b..56aa4a1c5b3 100644
--- a/AK/Platform.h
+++ b/AK/Platform.h
@@ -40,6 +40,11 @@
 #endif
 #define FLATTEN __attribute__((flatten))
 
+#ifdef RETURNS_NONNULL
+#    undef RETURNS_NONNULL
+#endif
+#define RETURNS_NONNULL __attribute__((returns_nonnull))
+
 #ifdef NO_SANITIZE_ADDRESS
 #    undef NO_SANITIZE_ADDRESS
 #endif