diff --git a/win32ss/user/user32/controls/button.c b/win32ss/user/user32/controls/button.c
index a9afe494c7a..7a4deca465d 100644
--- a/win32ss/user/user32/controls/button.c
+++ b/win32ss/user/user32/controls/button.c
@@ -389,7 +389,7 @@ LRESULT WINAPI ButtonWndProc_common(HWND hWnd, UINT uMsg,
 	    break;
 	/* fall through */
     case WM_LBUTTONUP:
-#ifdef _REACTOS_
+#ifdef __REACTOS__
         BOOL TellParent = FALSE; //// ReactOS see note below.
 #endif
         state = get_button_state( hWnd );
@@ -419,14 +419,14 @@ LRESULT WINAPI ButtonWndProc_common(HWND hWnd, UINT uMsg,
                                 (state & BST_INDETERMINATE) ? 0 : ((state & 3) + 1), 0 );
                 break;
             }
-#ifdef _REACTOS_
+#ifdef __REACTOS__
             TellParent = TRUE; // <---- Fix CORE-10194, Notify parent after capture is released.
 #else
             ReleaseCapture();
             BUTTON_NOTIFY_PARENT(hWnd, BN_CLICKED);
 #endif
         }
-#ifdef _REACTOS_
+#ifdef __REACTOS__
         ReleaseCapture();
         if (TellParent) BUTTON_NOTIFY_PARENT(hWnd, BN_CLICKED);
 #else