diff --git a/lib/cpp/test/ZlibTest.cpp b/lib/cpp/test/ZlibTest.cpp
index c9d3f38..9df9dc4 100644
--- a/lib/cpp/test/ZlibTest.cpp
+++ b/lib/cpp/test/ZlibTest.cpp
@@ -234,7 +234,7 @@
     }
     uint32_t got = zlib_trans->read(mirror.get() + tot, read_len);
     BOOST_REQUIRE_LE(got, expected_read_len);
-    BOOST_REQUIRE_NE(got, 0);
+    BOOST_REQUIRE_NE(got, (uint32_t) 0);
     tot += got;
   }
 
@@ -325,7 +325,7 @@
     TZlibTransport w_zlib_trans(membuf);
   }
 
-  BOOST_CHECK_EQUAL(membuf->available_read(), 0);
+  BOOST_CHECK_EQUAL(membuf->available_read(), (uint32_t) 0);
 }
 
 /*