diff --git a/tests/Writer32Test.cpp b/tests/Writer32Test.cpp
index 498be9c..e5b9363 100644
--- a/tests/Writer32Test.cpp
+++ b/tests/Writer32Test.cpp
@@ -187,18 +187,23 @@
         SkWriter32 writer(0);
         uint32_t storage[256];
         writer.reset(storage, sizeof(storage));
+        // These three writes are small enough to fit in storage.
         test1(reporter, &writer);
+        REPORTER_ASSERT(reporter, writer.wroteOnlyToStorage());
 
         writer.reset(storage, sizeof(storage));
         test2(reporter, &writer);
+        REPORTER_ASSERT(reporter, writer.wroteOnlyToStorage());
 
         writer.reset(storage, sizeof(storage));
         testWritePad(reporter, &writer);
+        REPORTER_ASSERT(reporter, writer.wroteOnlyToStorage());
 
-        // try overflowing the storage-block
+        // Try overflowing the storage-block.
         uint32_t smallStorage[8];
         writer.reset(smallStorage, sizeof(smallStorage));
         test2(reporter, &writer);
+        REPORTER_ASSERT(reporter, !writer.wroteOnlyToStorage());
     }
 
     // small storage