diff --git a/dll/cpl/joy/joy.c b/dll/cpl/joy/joy.c
index 97c49ed547e..530a78d442c 100644
--- a/dll/cpl/joy/joy.c
+++ b/dll/cpl/joy/joy.c
@@ -30,9 +30,8 @@
 
 #define NUM_APPLETS	(1)
 
-LONG CALLBACK SystemApplet(VOID);
+LONG CALLBACK SystemApplet(HWND hwnd, UINT uMsg, LPARAM lParam1, LPARAM lParam2);
 HINSTANCE hApplet = 0;
-HWND MainDlg;
 
 /* Applets */
 
@@ -262,11 +261,15 @@ MainPageProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
 
 /* First Applet */
 LONG CALLBACK
-SystemApplet(VOID)
+SystemApplet(HWND hwnd, UINT uMsg, LPARAM lParam1, LPARAM lParam2)
 {
+    UNREFERENCED_PARAMETER(uMsg);
+    UNREFERENCED_PARAMETER(lParam1);
+    UNREFERENCED_PARAMETER(lParam2);
+
     DialogBox(hApplet,
               MAKEINTRESOURCE(IDD_PROPPAGEMAIN),
-              MainDlg,
+              hwnd,
               MainPageProc);
 
     return (LONG)TRUE;
@@ -299,10 +302,7 @@ CPlApplet(HWND hwndCPl, UINT uMsg, LPARAM lParam1, LPARAM lParam2)
             break;
 
         case CPL_DBLCLK:
-            {
-                MainDlg = hwndCPl;
-                Applets[i].AppletProc();
-            }
+            Applets[i].AppletProc(hwndCPl, uMsg, lParam1, lParam2);
             break;
     }
 
diff --git a/dll/cpl/joy/joy.h b/dll/cpl/joy/joy.h
index 42d5f6f4d89..7ede1e01539 100644
--- a/dll/cpl/joy/joy.h
+++ b/dll/cpl/joy/joy.h
@@ -12,14 +12,12 @@
 
 #include "resource.h"
 
-typedef LONG (CALLBACK *CPLAPPLET_PROC)(VOID);
-
 typedef struct
 {
     int idIcon;
     int idName;
     int idDescription;
-    CPLAPPLET_PROC AppletProc;
+    APPLET_PROC AppletProc;
 } APPLET, *PAPPLET;
 
 typedef struct
@@ -28,7 +26,7 @@ typedef struct
     WCHAR szWorkingDirectory[MAX_PATH];
     WCHAR szDescription[MAX_PATH];
     WCHAR szLinkName[MAX_PATH];
-}CREATE_LINK_CONTEXT, *PCREATE_LINK_CONTEXT;
+} CREATE_LINK_CONTEXT, *PCREATE_LINK_CONTEXT;
 
 
 extern HINSTANCE hApplet;