diff --git a/src/UsefulBuf.c b/src/UsefulBuf.c
index c8e5d28..dcd7d34 100644
--- a/src/UsefulBuf.c
+++ b/src/UsefulBuf.c
@@ -105,7 +105,7 @@
       return NULLUsefulBufC;
    }
     
-   memcpy(Dest.ptr + uOffset, Src.ptr, Src.len);
+   memcpy((uint8_t *)Dest.ptr + uOffset, Src.ptr, Src.len);
     
    return((UsefulBufC){Dest.ptr, Src.len + uOffset});
 }