diff --git a/dlls/ole32/stg_prop.c b/dlls/ole32/stg_prop.c
index eeda2132ddd..84eaa2aac42 100644
--- a/dlls/ole32/stg_prop.c
+++ b/dlls/ole32/stg_prop.c
@@ -1981,9 +1981,8 @@ static HRESULT PropertyStorage_WritePropertyToStream(PropertyStorage_impl *This,
     {
         FILETIME temp;
 
-        StorageUtl_WriteULargeInteger((BYTE *)&temp, 0,
-         (const ULARGE_INTEGER *)&var->u.filetime);
-        hr = IStream_Write(This->stm, &temp, sizeof(FILETIME), &count);
+        StorageUtl_WriteULargeInteger(&temp, 0, (const ULARGE_INTEGER *)&var->u.filetime);
+        hr = IStream_Write(This->stm, &temp, sizeof(temp), &count);
         bytesWritten = count;
         break;
     }
diff --git a/dlls/ole32/storage32.c b/dlls/ole32/storage32.c
index 5fc1f59b784..52ecf590288 100644
--- a/dlls/ole32/storage32.c
+++ b/dlls/ole32/storage32.c
@@ -6982,17 +6982,16 @@ void StorageUtl_ReadULargeInteger(const BYTE* buffer, ULONG offset,
 #endif
 }
 
-void StorageUtl_WriteULargeInteger(BYTE* buffer, ULONG offset,
- const ULARGE_INTEGER *value)
+void StorageUtl_WriteULargeInteger(void *buffer, ULONG offset, const ULARGE_INTEGER *value)
 {
 #ifdef WORDS_BIGENDIAN
     ULARGE_INTEGER tmp;
 
     tmp.u.LowPart = htole32(value->u.HighPart);
     tmp.u.HighPart = htole32(value->u.LowPart);
-    memcpy(buffer + offset, &tmp, sizeof(ULARGE_INTEGER));
+    memcpy((BYTE *)buffer + offset, &tmp, sizeof(ULARGE_INTEGER));
 #else
-    memcpy(buffer + offset, value, sizeof(ULARGE_INTEGER));
+    memcpy((BYTE *)buffer + offset, value, sizeof(ULARGE_INTEGER));
 #endif
 }
 
diff --git a/dlls/ole32/storage32.h b/dlls/ole32/storage32.h
index bfd3a3121fa..f79f96e9293 100644
--- a/dlls/ole32/storage32.h
+++ b/dlls/ole32/storage32.h
@@ -561,8 +561,7 @@ void StorageUtl_ReadDWord(const BYTE* buffer, ULONG offset, DWORD* value) DECLSP
 void StorageUtl_WriteDWord(void *buffer, ULONG offset, DWORD value) DECLSPEC_HIDDEN;
 void StorageUtl_ReadULargeInteger(const BYTE* buffer, ULONG offset,
  ULARGE_INTEGER* value) DECLSPEC_HIDDEN;
-void StorageUtl_WriteULargeInteger(BYTE* buffer, ULONG offset,
- const ULARGE_INTEGER *value) DECLSPEC_HIDDEN;
+void StorageUtl_WriteULargeInteger(void *buffer, ULONG offset, const ULARGE_INTEGER *value) DECLSPEC_HIDDEN;
 void StorageUtl_ReadGUID(const BYTE* buffer, ULONG offset, GUID* value) DECLSPEC_HIDDEN;
 void StorageUtl_WriteGUID(void *buffer, ULONG offset, const GUID* value) DECLSPEC_HIDDEN;
 void StorageUtl_CopyDirEntryToSTATSTG(StorageBaseImpl *storage,STATSTG* destination,