diff --git a/dlls/comctl32/button.c b/dlls/comctl32/button.c
index 2f5a5b3f170..dccddf9f527 100644
--- a/dlls/comctl32/button.c
+++ b/dlls/comctl32/button.c
@@ -223,9 +223,10 @@ static inline void paint_button( HWND hwnd, LONG style, UINT action )
 /* retrieve the button text; returned buffer must be freed by caller */
 static inline WCHAR *get_button_text( HWND hwnd )
 {
-    static const INT len = 512;
+    INT len = GetWindowTextLengthW( hwnd );
     WCHAR *buffer = HeapAlloc( GetProcessHeap(), 0, (len + 1) * sizeof(WCHAR) );
-    if (buffer) InternalGetWindowText( hwnd, buffer, len + 1 );
+    if (buffer)
+        GetWindowTextW( hwnd, buffer, len + 1 );
     return buffer;
 }