diff --git a/ci.sh b/ci.sh
index bdca26fd0491..080bd9204db5 100755
--- a/ci.sh
+++ b/ci.sh
@@ -26,8 +26,7 @@ function run_tests {
     # optimizations up all the way).
     # Optimizations change diagnostics (mostly backtraces), so we don't check them
     #FIXME(#2155): we want to only run the pass and panic tests here, not the fail tests.
-    #MIRIFLAGS="-O -Zmir-opt-level=4" MIRI_SKIP_UI_CHECKS=1 ./miri test --locked
-    true
+    MIRIFLAGS="-O -Zmir-opt-level=4" MIRI_SKIP_UI_CHECKS=1 ./miri test --locked -- tests/{run-pass,run-fail}
   fi
 
   # On Windows, there is always "python", not "python3" or "python2".