diff --git a/dlls/rpcrt4/cpsf.c b/dlls/rpcrt4/cpsf.c
index 49930d913fe..d4c021e8cd3 100644
--- a/dlls/rpcrt4/cpsf.c
+++ b/dlls/rpcrt4/cpsf.c
@@ -160,7 +160,7 @@ HRESULT WINAPI NdrDllRegisterProxy(HMODULE hDll,
   HKEY key, subkey;
 
   TRACE("(%p,%p,%s)\n", hDll, pProxyFileList, debugstr_guid(pclsid));
-  UuidToStringA((UUID*)pclsid, &clsid);
+  UuidToStringA((UUID*)pclsid, (unsigned char**)&clsid);
 
   /* register interfaces to point to clsid */
   while (*pProxyFileList) {
@@ -172,9 +172,9 @@ HRESULT WINAPI NdrDllRegisterProxy(HMODULE hDll,
 
       TRACE("registering %s %s => %s\n", name, debugstr_guid(proxy->header.piid), clsid);
 
-      UuidToStringA((UUID*)proxy->header.piid, &iid);
+      UuidToStringA((UUID*)proxy->header.piid, (unsigned char**)&iid);
       snprintf(keyname, sizeof(keyname), "Interface\\%s", iid);
-      RpcStringFreeA(&iid);
+      RpcStringFreeA((unsigned char**)&iid);
       if (RegCreateKeyExA(HKEY_CLASSES_ROOT, keyname, 0, NULL, 0,
                           KEY_WRITE, NULL, &key, NULL) == ERROR_SUCCESS) {
         if (name)
@@ -205,7 +205,7 @@ HRESULT WINAPI NdrDllRegisterProxy(HMODULE hDll,
   }
 
   /* done */
-  RpcStringFreeA(&clsid);
+  RpcStringFreeA((unsigned char**)&clsid);
   return S_OK;
 }
 
@@ -220,7 +220,7 @@ HRESULT WINAPI NdrDllUnregisterProxy(HMODULE hDll,
   char keyname[120], module[120];
 
   TRACE("(%p,%p,%s)\n", hDll, pProxyFileList, debugstr_guid(pclsid));
-  UuidToStringA((UUID*)pclsid, &clsid);
+  UuidToStringA((UUID*)pclsid, (unsigned char**)&clsid);
 
   /* unregister interfaces */
   while (*pProxyFileList) {
@@ -232,9 +232,9 @@ HRESULT WINAPI NdrDllUnregisterProxy(HMODULE hDll,
 
       TRACE("unregistering %s %s <= %s\n", name, debugstr_guid(proxy->header.piid), clsid);
 
-      UuidToStringA((UUID*)proxy->header.piid, &iid);
+      UuidToStringA((UUID*)proxy->header.piid, (unsigned char**)&iid);
       snprintf(keyname, sizeof(keyname), "Interface\\%s", iid);
-      RpcStringFreeA(&iid);
+      RpcStringFreeA((unsigned char**)&iid);
       RegDeleteKeyA(HKEY_CLASSES_ROOT, keyname);
     }
     pProxyFileList++;
@@ -247,6 +247,6 @@ HRESULT WINAPI NdrDllUnregisterProxy(HMODULE hDll,
   RegDeleteKeyA(HKEY_CLASSES_ROOT, keyname);
 
   /* done */
-  RpcStringFreeA(&clsid);
+  RpcStringFreeA((unsigned char**)&clsid);
   return S_OK;
 }
diff --git a/dlls/rpcrt4/rpc_binding.c b/dlls/rpcrt4/rpc_binding.c
index a6eb28f0280..01a070f25c7 100644
--- a/dlls/rpcrt4/rpc_binding.c
+++ b/dlls/rpcrt4/rpc_binding.c
@@ -595,11 +595,11 @@ RPC_STATUS WINAPI RpcStringBindingParseA( LPSTR StringBinding, LPSTR *ObjUuid,
   return RPC_S_OK;
 
 fail:
-  if (ObjUuid) RpcStringFreeA(ObjUuid);
-  if (Protseq) RpcStringFreeA(Protseq);
-  if (NetworkAddr) RpcStringFreeA(NetworkAddr);
-  if (Endpoint) RpcStringFreeA(Endpoint);
-  if (Options) RpcStringFreeA(Options);
+  if (ObjUuid) RpcStringFreeA((unsigned char**)ObjUuid);
+  if (Protseq) RpcStringFreeA((unsigned char**)Protseq);
+  if (NetworkAddr) RpcStringFreeA((unsigned char**)NetworkAddr);
+  if (Endpoint) RpcStringFreeA((unsigned char**)Endpoint);
+  if (Options) RpcStringFreeA((unsigned char**)Options);
   return RPC_S_INVALID_STRING_BINDING;
 }
 
@@ -771,11 +771,11 @@ RPC_STATUS WINAPI RpcBindingFromStringBindingA( LPSTR StringBinding, RPC_BINDING
   if (ret == RPC_S_OK)
     ret = RPCRT4_CompleteBindingA(bind, NetworkAddr, Endpoint, Options);
 
-  RpcStringFreeA(&Options);
-  RpcStringFreeA(&Endpoint);
-  RpcStringFreeA(&NetworkAddr);
-  RpcStringFreeA(&Protseq);
-  RpcStringFreeA(&ObjectUuid);
+  RpcStringFreeA((unsigned char**)&Options);
+  RpcStringFreeA((unsigned char**)&Endpoint);
+  RpcStringFreeA((unsigned char**)&NetworkAddr);
+  RpcStringFreeA((unsigned char**)&Protseq);
+  RpcStringFreeA((unsigned char**)&ObjectUuid);
 
   if (ret == RPC_S_OK) 
     *Binding = (RPC_BINDING_HANDLE)bind;
@@ -835,13 +835,13 @@ RPC_STATUS WINAPI RpcBindingToStringBindingA( RPC_BINDING_HANDLE Binding, LPSTR*
 
   TRACE("(%p,%p)\n", Binding, StringBinding);
 
-  ret = UuidToStringA(&bind->ObjectUuid, &ObjectUuid);
+  ret = UuidToStringA(&bind->ObjectUuid, (unsigned char**)&ObjectUuid);
   if (ret != RPC_S_OK) return ret;
 
   ret = RpcStringBindingComposeA(ObjectUuid, bind->Protseq, bind->NetworkAddr,
                                  bind->Endpoint, NULL, StringBinding);
 
-  RpcStringFreeA(&ObjectUuid);
+  RpcStringFreeA((unsigned char**)&ObjectUuid);
 
   return ret;
 }
@@ -856,7 +856,7 @@ RPC_STATUS WINAPI RpcBindingToStringBindingW( RPC_BINDING_HANDLE Binding, LPWSTR
   TRACE("(%p,%p)\n", Binding, StringBinding);
   ret = RpcBindingToStringBindingA(Binding, &str);
   *StringBinding = RPCRT4_strdupAtoW(str);
-  RpcStringFreeA(&str);
+  RpcStringFreeA((unsigned char**)&str);
   return ret;
 }
   
diff --git a/dlls/rpcrt4/rpcrt4_main.c b/dlls/rpcrt4/rpcrt4_main.c
index d718d3ba093..8e6b41faba0 100644
--- a/dlls/rpcrt4/rpcrt4_main.c
+++ b/dlls/rpcrt4/rpcrt4_main.c
@@ -190,7 +190,7 @@ BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
  *
  *  S_OK if successful.
  */
-RPC_STATUS WINAPI RpcStringFreeA(LPSTR* String)
+RPC_STATUS WINAPI RpcStringFreeA(unsigned char** String)
 {
   HeapFree( GetProcessHeap(), 0, *String);
 
@@ -206,7 +206,7 @@ RPC_STATUS WINAPI RpcStringFreeA(LPSTR* String)
  *
  *  S_OK if successful.
  */
-RPC_STATUS WINAPI RpcStringFreeW(LPWSTR* String)
+RPC_STATUS WINAPI RpcStringFreeW(unsigned short** String)
 {
   HeapFree( GetProcessHeap(), 0, *String);
 
@@ -545,7 +545,7 @@ unsigned short WINAPI UuidHash(UUID *uuid, RPC_STATUS *Status)
  *  S_OK if successful.
  *  S_OUT_OF_MEMORY if unsucessful.
  */
-RPC_STATUS WINAPI UuidToStringA(UUID *Uuid, LPSTR* StringUuid)
+RPC_STATUS WINAPI UuidToStringA(UUID *Uuid, unsigned char** StringUuid)
 {
   *StringUuid = HeapAlloc( GetProcessHeap(), 0, sizeof(char) * 37);
 
@@ -571,7 +571,7 @@ RPC_STATUS WINAPI UuidToStringA(UUID *Uuid, LPSTR* StringUuid)
  *  S_OK if successful.
  *  S_OUT_OF_MEMORY if unsucessful.
  */
-RPC_STATUS WINAPI UuidToStringW(UUID *Uuid, LPWSTR* StringUuid)
+RPC_STATUS WINAPI UuidToStringW(UUID *Uuid, unsigned short** StringUuid)
 {
   char buf[37];
 
@@ -605,7 +605,7 @@ static const BYTE hex2bin[] =
 /***********************************************************************
  *		UuidFromStringA (RPCRT4.@)
  */
-RPC_STATUS WINAPI UuidFromStringA(LPSTR str, UUID *uuid)
+RPC_STATUS WINAPI UuidFromStringA(unsigned char* str, UUID *uuid)
 {
     BYTE *s = (BYTE *)str;
     int i;
@@ -646,7 +646,7 @@ RPC_STATUS WINAPI UuidFromStringA(LPSTR str, UUID *uuid)
 /***********************************************************************
  *		UuidFromStringW (RPCRT4.@)
  */
-RPC_STATUS WINAPI UuidFromStringW(LPWSTR s, UUID *uuid)
+RPC_STATUS WINAPI UuidFromStringW(unsigned short* s, UUID *uuid)
 {
     int i;
 
diff --git a/dlls/rpcrt4/tests/rpc.c b/dlls/rpcrt4/tests/rpc.c
index 7b4e45eb0b9..8b050b6ecda 100644
--- a/dlls/rpcrt4/tests/rpc.c
+++ b/dlls/rpcrt4/tests/rpc.c
@@ -86,7 +86,7 @@ void UuidConversionAndComparison(void) {
     /* Uuid to String to Uuid (char) */
     for (i1 = 0; i1 < 10; i1++) {
         Uuid1 = Uuid_Table[i1];
-	ok( (UuidToStringA(&Uuid1, &str) == RPC_S_OK), "Simple UUID->String copy" );
+	ok( (UuidToStringA(&Uuid1, (unsigned char**)&str) == RPC_S_OK), "Simple UUID->String copy" );
 	ok( (UuidFromStringA(str, &Uuid2) == RPC_S_OK), "Simple String->UUID copy from generated UUID String" );
 	ok( UuidEqual(&Uuid1, &Uuid2, &rslt), "Uuid -> String -> Uuid transform" );
 	/* invalid uuid tests  -- size of valid UUID string=36 */
diff --git a/include/rpcdce.h b/include/rpcdce.h
index 8026023ae32..c0b4e55d308 100644
--- a/include/rpcdce.h
+++ b/include/rpcdce.h
@@ -250,21 +250,21 @@ RPCRTAPI RPC_STATUS RPC_ENTRY
 #define RpcStringBindingCompose WINELIB_NAME_AW(RpcStringBindingCompose)
 
 RPCRTAPI RPC_STATUS RPC_ENTRY
-  RpcStringFreeA(LPSTR* String);
+  RpcStringFreeA(unsigned char** String);
 RPCRTAPI RPC_STATUS RPC_ENTRY
-  RpcStringFreeW(LPWSTR* String);
+  RpcStringFreeW(unsigned short** String);
 #define RpcStringFree WINELIB_NAME_AW(RpcStringFree)
 
 RPCRTAPI RPC_STATUS RPC_ENTRY
-  UuidToStringA( UUID* Uuid, LPSTR* StringUuid );
+  UuidToStringA( UUID* Uuid, unsigned char** StringUuid );
 RPCRTAPI RPC_STATUS RPC_ENTRY
-  UuidToStringW( UUID* Uuid, LPWSTR* StringUuid );
+  UuidToStringW( UUID* Uuid, unsigned short** StringUuid );
 #define UuidToString WINELIB_NAME_AW(UuidToString)
 
 RPCRTAPI RPC_STATUS RPC_ENTRY
-  UuidFromStringA( LPSTR StringUuid, UUID* Uuid );
+  UuidFromStringA( unsigned char* StringUuid, UUID* Uuid );
 RPCRTAPI RPC_STATUS RPC_ENTRY
-  UuidFromStringW( LPWSTR StringUuid, UUID* Uuid );
+  UuidFromStringW( unsigned short* StringUuid, UUID* Uuid );
 #define UuidFromString WINELIB_NAME_AW(UuidFromString)
 
 RPCRTAPI RPC_STATUS RPC_ENTRY