diff --git a/repertory.iss.in b/repertory.iss.in
index 36788583..4b7265d7 100644
--- a/repertory.iss.in
+++ b/repertory.iss.in
@@ -39,16 +39,19 @@ type
   LRESULT = LongWord;
   WPARAM = LongWord;
 
-function SendMessageTimeout(hWnd: HWND; Msg: UINT; wParam: WPARAM; lParam: LPARAM;
+function SendMessageTimeout(hWnd: HWND; Msg: UINT; wParam: WPARAM; lParam: WideString;
   fuFlags: UINT; uTimeout: UINT; out lpdwResult: DWORD): LRESULT;
   external 'SendMessageTimeoutW@user32.dll stdcall';
 
 procedure RefreshEnvironment();
 var
+  EnvStr: WideString;
   R: DWORD;
 begin
-  SendMessageTimeout(HWND_BROADCAST, WM_SETTINGCHANGE, 0,
-    'Environment', SMTO_ABORTIFHUNG, 5000, R);
+  EnvStr := 'Environment' + #0 + #0;
+
+  SendMessageTimeout(HWND_BROADCAST, WM_SETTINGCHANGE, 0, 
+    EnvStr, SMTO_ABORTIFHUNG, 5000, R);
 end;
 
 function NormalizeSemicolons(S: string): string;