diff --git a/reactos/lib/shell32/shell32.spec b/reactos/lib/shell32/shell32.spec
index ab0768930d1..a19a38f7ba8 100644
--- a/reactos/lib/shell32/shell32.spec
+++ b/reactos/lib/shell32/shell32.spec
@@ -95,7 +95,7 @@
   99 stdcall SetAppStartingCursor (long long)
  100 stdcall SHRestricted(long)
 
- 102 stdcall SHCoCreateInstance(ptr ptr long ptr ptr)
+ 102 stdcall SHCoCreateInstance(wstr ptr long ptr ptr)
  103 stdcall SignalFileOpen(long)
  104 stdcall FileMenu_DeleteAllItems(long)
  105 stdcall FileMenu_DrawItem(long ptr)
diff --git a/reactos/lib/shell32/shellole.c b/reactos/lib/shell32/shellole.c
index a079e77856f..ade449ec821 100644
--- a/reactos/lib/shell32/shellole.c
+++ b/reactos/lib/shell32/shellole.c
@@ -123,8 +123,8 @@ DWORD WINAPI __SHGUIDToStringW (REFGUID guid, LPWSTR str)
 /************************************************************************/
 
 LRESULT WINAPI SHCoCreateInstance(
-	LPCSTR aclsid,
-	REFCLSID clsid,
+	LPCWSTR aclsid,
+	const CLSID *clsid,
 	LPUNKNOWN pUnkOuter,
 	REFIID refiid,
 	LPVOID *ppv)
@@ -151,7 +151,7 @@ LRESULT WINAPI SHCoCreateInstance(
 	if (!clsid)
 	{
 	  if (!aclsid) return REGDB_E_CLASSNOTREG;
-	  SHCLSIDFromStringA(aclsid, &iid);
+	  SHCLSIDFromStringW(aclsid, &iid);
 	  myclsid = &iid;
 	}
 
@@ -280,7 +280,7 @@ DWORD WINAPI SHCLSIDFromStringA (LPCSTR clsid, CLSID *id)
         return CO_E_CLASSSTRING;
     return CLSIDFromString( buffer, id );
 }
-DWORD WINAPI SHCLSIDFromStringW (LPWSTR clsid, CLSID *id)
+DWORD WINAPI SHCLSIDFromStringW (LPCWSTR clsid, CLSID *id)
 {
 	TRACE("(%p(%s) %p)\n", clsid, debugstr_w(clsid), id);
 	return CLSIDFromString(clsid, id);
diff --git a/reactos/lib/shell32/undocshell.h b/reactos/lib/shell32/undocshell.h
index 700bd11a35e..120e42bd92e 100644
--- a/reactos/lib/shell32/undocshell.h
+++ b/reactos/lib/shell32/undocshell.h
@@ -831,14 +831,7 @@ HRESULT WINAPI SHCreateDefClassObject(
 	REFIID riidObject);
 
 DWORD WINAPI SHCLSIDFromStringA (LPCSTR clsid, CLSID *id);
-DWORD WINAPI SHCLSIDFromStringW (LPWSTR clsid, CLSID *id);
-
-HRESULT WINAPI SHCoCreateInstance(
-	LPCSTR lpszClsid,
-	REFCLSID rClsid,
-	LPUNKNOWN pUnkOuter,
-	REFIID riid,
-	LPVOID *ppv);
+DWORD WINAPI SHCLSIDFromStringW (LPCWSTR clsid, CLSID *id);
 
 void WINAPI SHFreeUnusedLibraries();