diff --git a/tests.cpp b/tests.cpp
index aaaf2fe..f59c5ef 100644
--- a/tests.cpp
+++ b/tests.cpp
@@ -133,7 +133,8 @@ void interpreterTests() {
 	       (-3 < -2 < -1) and
 	       (3 > 2 > 1)
        )", "1"},
-       {"5 + + 1", "6"}
+       {"5 + + 1", "6"},
+       {"5*-1", "-5"}
       });
   for (unsigned int i = 0; i < tests.size(); i++) {
     std::string result = std::to_string(