diff --git a/circleci.sh b/circleci.sh
index f9c40461b0c0..438e9447f150 100755
--- a/circleci.sh
+++ b/circleci.sh
@@ -114,7 +114,7 @@ coverage()
     make -j$N -C src -f posix.mak MODEL=$MODEL HOST_DMD=../_${build_path}/host_dmd clean
     make -j$N -C src -f posix.mak MODEL=$MODEL HOST_DMD=../_${build_path}/host_dmd ENABLE_COVERAGE=1
 
-    make -j$N -C test MODEL=$MODEL ARGS="-O -inline -release" DMD_TEST_COVERAGE=1
+    make -j1 -C test MODEL=$MODEL ARGS="-O -inline -release" DMD_TEST_COVERAGE=1
 }
 
 codecov()