diff --git a/ConflictSet.cpp b/ConflictSet.cpp
index e7e648e..cf25030 100644
--- a/ConflictSet.cpp
+++ b/ConflictSet.cpp
@@ -4242,6 +4242,15 @@ struct __attribute__((visibility("hidden"))) ConflictSet::Impl {
       inProgress->continuation(inProgress, &context);
     }
 
+#ifndef NDEBUG
+    Arena arena;
+    auto *results2 = new (arena) Result[count];
+    CheckContext context2;
+    context.tls.impl = this;
+    useSequential(reads, results2, count, context2);
+    assert(memcmp(result, results2, count) == 0);
+#endif
+
 #else
     useSequential(reads, result, count, context);
 #endif
diff --git a/LongestCommonPrefix.h b/LongestCommonPrefix.h
index 5490f97..98da7c2 100644
--- a/LongestCommonPrefix.h
+++ b/LongestCommonPrefix.h
@@ -129,7 +129,7 @@ longestCommonPrefix(const uint8_t *ap, const uint8_t *bp, int cl) {
   }
 
   int i = 0;
-  int end;
+  int end; // GCOVR_EXCL_LINE
 
   // kStride * kUnrollCount at a time
   end = cl & ~(kStride * kUnrollFactor - 1);