diff --git a/tests/safety/mutation.sh b/tests/safety/mutation.sh
index e8c242cab..9b40bdedd 100755
--- a/tests/safety/mutation.sh
+++ b/tests/safety/mutation.sh
@@ -8,7 +8,8 @@ $DIR/install_mull.sh
 
 GIT_REF="${GIT_REF:-origin/master}"
 GIT_ROOT=$(git rev-parse --show-toplevel)
-echo -e "mutators:\n  - cxx_all" > $GIT_ROOT/mull.yml
+MULL_OPS="mutators: [cxx_increment, cxx_decrement, cxx_comparison, cxx_boundary, cxx_bitwise_assignment, cxx_bitwise, cxx_arithmetic_assignment, cxx_arithmetic]"
+echo -e "$MULL_OPS" > $GIT_ROOT/mull.yml
 scons --mutation -j$(nproc) -D
 echo -e "timeout: 10000\ngitDiffRef: $GIT_REF\ngitProjectRoot: $GIT_ROOT" >> $GIT_ROOT/mull.yml