diff --git a/.travis/run-tests.sh b/.travis/run-tests.sh
index 11d98cd6..9334e959 100755
--- a/.travis/run-tests.sh
+++ b/.travis/run-tests.sh
@@ -8,7 +8,7 @@ for tested in "${testedcomponents[@]}"
     do
         echo "$tested:"
         phpunit -c $testdir/phpunit.xml $testdir/$tested
-        let "result = $result || $?"
+        result=$(($result || $?))
 done
 
-exit $result
\ No newline at end of file
+exit $result