diff --git a/include/cpl.h b/include/cpl.h
index 5c382ffae11..adabeba8484 100644
--- a/include/cpl.h
+++ b/include/cpl.h
@@ -36,7 +36,7 @@ typedef struct tagCPLINFO {
     int     idIcon;
     int     idName;
     int     idInfo;
-    LONG    lData;
+    LONG_PTR lData;
 } CPLINFO, *LPCPLINFO;
 
 typedef struct tagNEWCPLINFOA
@@ -44,7 +44,7 @@ typedef struct tagNEWCPLINFOA
     DWORD   dwSize;
     DWORD   dwFlags;
     DWORD   dwHelpContext;
-    LONG    lData;
+    LONG_PTR lData;
     HICON   hIcon;
     CHAR    szName[32];
     CHAR    szInfo[64];
@@ -56,7 +56,7 @@ typedef struct tagNEWCPLINFOW
     DWORD   dwSize;
     DWORD   dwFlags;
     DWORD   dwHelpContext;
-    LONG    lData;
+    LONG_PTR lData;
     HICON   hIcon;
     WCHAR   szName[32];
     WCHAR   szInfo[64];