diff --git a/libuavcan/test/marshal/float_spec.cpp b/libuavcan/test/marshal/float_spec.cpp
index 7a55aee944..eacc0522fe 100644
--- a/libuavcan/test/marshal/float_spec.cpp
+++ b/libuavcan/test/marshal/float_spec.cpp
@@ -68,7 +68,7 @@ TEST(FloatSpec, Basic)
         -std::numeric_limits<double>::infinity(),
         nanl("")
     };
-    static const int NumValues = sizeof(Values) / sizeof(Values[0]);
+    static const int NumValues = int(sizeof(Values) / sizeof(Values[0]));
 
     static const long double ValuesF16S[] =
     {
diff --git a/libuavcan/test/transport/transfer_receiver.cpp b/libuavcan/test/transport/transfer_receiver.cpp
index c6c3f6ab4d..e6c379d39e 100644
--- a/libuavcan/test/transport/transfer_receiver.cpp
+++ b/libuavcan/test/transport/transfer_receiver.cpp
@@ -322,7 +322,7 @@ TEST(TransferReceiver, IntervalMeasurement)
         ASSERT_EQ(0x3231, rcv.getLastTransferCrc());
         ASSERT_EQ(timestamp, rcv.getLastTransferTimestampMonotonic().toUSec());
 
-        timestamp += INTERVAL;
+        timestamp += uint64_t(INTERVAL);
         tid.increment();
     }