diff --git a/Jenkinsfile b/Jenkinsfile
index b12ba7e05b..b4f2d9e93d 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -68,7 +68,7 @@ pipeline {
                    """
                         sh """
           cd performance-tests-cmdstan
-          echo "CXXFLAGS+=-march=haswell" > cmdstan/make/local
+          echo "CXXFLAGS+=-march=core2 -fno-fast-math" > cmdstan/make/local
           cat known_good_perf_all.tests
           CXX="${CXX}" ./compare-compilers.sh "--tests-file=known_good_perf_all.tests --num-samples=10" "\$(readlink -f ../bin/stanc)"
            cd ..
@@ -103,7 +103,7 @@ pipeline {
           echo "example-models/regression_tests/mother.stan" > all.tests
           cat known_good_perf_all.tests shotgun_perf_all.tests >> all.tests
           cat all.tests
-          echo "CXXFLAGS+=-march=haswell" > cmdstan/make/local
+          echo "CXXFLAGS+=-march=core2 -fno-fast-math" > cmdstan/make/local
           CXX="${CXX}" ./compare-compilers.sh "--tests-file all.tests --num-samples=10" "\$(readlink -f ../bin/stanc)"  || true
                """
                         xunit([GoogleTest(