diff --git a/dlls/user32/dde_misc.c b/dlls/user32/dde_misc.c
index 16f36d52d7c..1f4915f4d42 100644
--- a/dlls/user32/dde_misc.c
+++ b/dlls/user32/dde_misc.c
@@ -864,7 +864,7 @@ ATOM	WDML_MakeAtomFromHsz(HSZ hsz)
  * Generally used while receiving a global atom and transforming it
  * into an HSZ
  */
-HSZ	WDML_MakeHszFromAtom(WDML_INSTANCE* pInstance, ATOM atom)
+HSZ	WDML_MakeHszFromAtom(const WDML_INSTANCE* pInstance, ATOM atom)
 {
     WCHAR nameBuffer[MAX_BUFFER_LEN];
 
diff --git a/dlls/user32/dde_private.h b/dlls/user32/dde_private.h
index 4ee93fbd1ec..56c2024e096 100644
--- a/dlls/user32/dde_private.h
+++ b/dlls/user32/dde_private.h
@@ -223,7 +223,7 @@ extern	void 		WDML_FreeAllHSZ(WDML_INSTANCE* pInstance) DECLSPEC_HIDDEN;
 extern	BOOL		WDML_DecHSZ(WDML_INSTANCE* pInstance, HSZ hsz) DECLSPEC_HIDDEN;
 extern	BOOL		WDML_IncHSZ(WDML_INSTANCE* pInstance, HSZ hsz) DECLSPEC_HIDDEN;
 extern	ATOM		WDML_MakeAtomFromHsz(HSZ hsz) DECLSPEC_HIDDEN;
-extern	HSZ		WDML_MakeHszFromAtom(WDML_INSTANCE* pInstance, ATOM atom) DECLSPEC_HIDDEN;
+extern	HSZ		WDML_MakeHszFromAtom(const WDML_INSTANCE* pInstance, ATOM atom) DECLSPEC_HIDDEN;
 /* client calls these */
 extern	WDML_XACT*	WDML_AllocTransaction(WDML_INSTANCE* pInstance, UINT ddeMsg, UINT wFmt, HSZ hszItem) DECLSPEC_HIDDEN;
 extern	void		WDML_QueueTransaction(WDML_CONV* pConv, WDML_XACT* pXAct) DECLSPEC_HIDDEN;