Fix warnings
diff --git a/test/api/test-blob.c b/test/api/test-blob.c
index 6759920..bbb7e2e 100644
--- a/test/api/test-blob.c
+++ b/test/api/test-blob.c
@@ -270,7 +270,7 @@
 
   if (mm == HB_MEMORY_MODE_DUPLICATE) {
     g_assert_cmpint (fixture->freed, ==, 1);
-    fixture->data = hb_blob_get_data (b, NULL);
+    fixture->data = (char *) hb_blob_get_data (b, NULL);
   } else {
     g_assert_cmpint (fixture->freed, ==, 0);
   }