diff --git a/tests/malloc_test.cpp b/tests/malloc_test.cpp
index 14a426f..2b48d85 100644
--- a/tests/malloc_test.cpp
+++ b/tests/malloc_test.cpp
@@ -935,7 +935,8 @@
   size_t expected_alignment = alignof(Type);
   if (expected_alignment != 0) {
     ASSERT_EQ(0U, (expected_alignment - 1) & reinterpret_cast<uintptr_t>(floating))
-        << "Expected alignment " << expected_alignment << " ptr value " << floating;
+        << "Expected alignment " << expected_alignment << " ptr value "
+        << static_cast<void*>(floating);
   }
 }