diff --git a/src/runtime2/tests/sync_failure.rs b/src/runtime2/tests/sync_failure.rs
index 392b8a22fa18fbf5c6fe934059189f7bfd84bea9..f3acdabcf1fbbd962ce73e7fe41de47edde701db 100644
--- a/src/runtime2/tests/sync_failure.rs
+++ b/src/runtime2/tests/sync_failure.rs
@@ -36,7 +36,9 @@ fn test_local_sync_failure() {
 #[test]
 fn test_shared_sync_failure() {
     // Same as above. One of the components should fail, the other should follow
-    // suit because it cannot complete a sync round.
+    // suit because it cannot complete a sync round. We intentionally have an
+    // infinite loop in the while condition because we need at least two loops
+    // for the last error to get picked up.
     const CODE: &'static str = "
     enum Location { BeforeSync, AfterPut, AfterGet, AfterSync, Never }
     primitive failing_at_location(in<bool> input, out<bool> output, Location loc) {
@@ -63,7 +65,7 @@ fn test_shared_sync_failure() {
     ";
 
     run_test_in_runtime(CODE, |api| {
-        for variant in 0..1 {
+        for variant in 0..4 { // all `Location` enum variants, except `Never`.
             // Create the channels
             api.create_connector("", "constructor", ValueGroup::new_stack(vec![
                 Value::Enum(variant)