diff --git a/ci/common/build.bash b/ci/common/build.bash
index 9a897e9cb9..46054c4acd 100755
--- a/ci/common/build.bash
+++ b/ci/common/build.bash
@@ -289,8 +289,13 @@ set -e
 
 log "Test Thrust and CUB..."
 
-echo_and_run_timed "Test" ctest ${CTEST_FLAGS} | tee ctest_log
-test_status=$?
+(
+  # Make sure test_status captures ctest, not tee:
+  # https://stackoverflow.com/a/999259/11130318
+  set -o pipefail
+  echo_and_run_timed "Test" ctest ${CTEST_FLAGS} | tee ctest_log
+  test_status=$?
+)
 
 ################################################################################
 # COMPILE TIME INFO: Print the 20 longest running build steps (ninja only)