diff --git a/reactos/dll/ntdll/ldr/ldrapi.c b/reactos/dll/ntdll/ldr/ldrapi.c
index ad56964d7ea..9b697ca9a0e 100644
--- a/reactos/dll/ntdll/ldr/ldrapi.c
+++ b/reactos/dll/ntdll/ldr/ldrapi.c
@@ -532,7 +532,7 @@ LdrQueryProcessModuleInformation(IN PRTL_PROCESS_MODULES ModuleInformation,
 
 NTSTATUS
 NTAPI
-LdrEnumerateLoadedModules(BOOLEAN ReservedFlag, PLDR_ENUM_CALLBACK EnumProc, ULONG Context)
+LdrEnumerateLoadedModules(BOOLEAN ReservedFlag, PLDR_ENUM_CALLBACK EnumProc, PVOID Context)
 {
     PLIST_ENTRY ListHead, ListEntry;
     PLDR_DATA_TABLE_ENTRY LdrEntry;
diff --git a/reactos/include/ndk/ldrfuncs.h b/reactos/include/ndk/ldrfuncs.h
index 8b967fa8e3d..1bf8a83d32c 100644
--- a/reactos/include/ndk/ldrfuncs.h
+++ b/reactos/include/ndk/ldrfuncs.h
@@ -123,7 +123,7 @@ NTAPI
 LdrEnumerateLoadedModules(
     IN BOOLEAN ReservedFlag,
     IN PLDR_ENUM_CALLBACK EnumProc,
-    IN ULONG Context
+    IN PVOID Context
 );
 
 #endif
diff --git a/reactos/include/ndk/ldrtypes.h b/reactos/include/ndk/ldrtypes.h
index fbfa381638b..49ebe38cd55 100644
--- a/reactos/include/ndk/ldrtypes.h
+++ b/reactos/include/ndk/ldrtypes.h
@@ -191,7 +191,7 @@ typedef struct _ALT_RESOURCE_MODULE
 //
 // Callback function for LdrEnumerateLoadedModules
 //
-typedef NTSTATUS (NTAPI LDR_ENUM_CALLBACK)(IN PLDR_DATA_TABLE_ENTRY ModuleInformation, IN ULONG Parameter, OUT BOOLEAN *Stop);
+typedef NTSTATUS (NTAPI LDR_ENUM_CALLBACK)(IN PLDR_DATA_TABLE_ENTRY ModuleInformation, IN PVOID Parameter, OUT BOOLEAN *Stop);
 typedef LDR_ENUM_CALLBACK *PLDR_ENUM_CALLBACK;
 
 #endif