diff --git a/libuavcan/include/uavcan/marshal/integer_spec.hpp b/libuavcan/include/uavcan/marshal/integer_spec.hpp
index f4a4eb2754..14c2cb7485 100644
--- a/libuavcan/include/uavcan/marshal/integer_spec.hpp
+++ b/libuavcan/include/uavcan/marshal/integer_spec.hpp
@@ -64,7 +64,7 @@ private:
     {
         static StorageType max()
         {
-            return StorageType((IsSigned != 0) ? 0x7FFFFFFFFFFFFFFFLL : 0xFFFFFFFFFFFFFFFFULL);
+            return StorageType((IsSigned == 0) ? 0xFFFFFFFFFFFFFFFFULL : 0x7FFFFFFFFFFFFFFFLL);
         }
         static UnsignedStorageType mask() { return 0xFFFFFFFFFFFFFFFFULL; }
     };