diff --git a/source/fuzz/shrinker.cpp b/source/fuzz/shrinker.cpp
index 85a06fd83..829df63ee 100644
--- a/source/fuzz/shrinker.cpp
+++ b/source/fuzz/shrinker.cpp
@@ -121,11 +121,13 @@ Shrinker::ShrinkerResultStatus Shrinker::Run(
   // succeeds, (b) get the binary that results from running these
   // transformations, and (c) get the subsequence of the initial transformations
   // that actually apply (in principle this could be a strict subsequence).
-  if (Replayer(impl_->target_env, impl_->validate_during_replay,
-               impl_->validator_options)
-          .Run(binary_in, initial_facts, transformation_sequence_in,
-               transformation_sequence_in.transformation_size(),
-               &current_best_binary, &current_best_transformations) !=
+  Replayer replayer(impl_->target_env, impl_->validate_during_replay,
+                    impl_->validator_options);
+  replayer.SetMessageConsumer(impl_->consumer);
+  if (replayer.Run(binary_in, initial_facts, transformation_sequence_in,
+                   static_cast<uint32_t>(
+                       transformation_sequence_in.transformation_size()),
+                   &current_best_binary, &current_best_transformations) !=
       Replayer::ReplayerResultStatus::kComplete) {
     return ShrinkerResultStatus::kReplayFailed;
   }
@@ -185,7 +187,8 @@ Shrinker::ShrinkerResultStatus Shrinker::Run(
       // Remove a chunk of transformations according to the current index and
       // chunk size.
       auto transformations_with_chunk_removed =
-          RemoveChunk(current_best_transformations, chunk_index, chunk_size);
+          RemoveChunk(current_best_transformations,
+                      static_cast<uint32_t>(chunk_index), chunk_size);
 
       // Replay the smaller sequence of transformations to get a next binary and
       // transformation sequence. Note that the transformations arising from
@@ -194,11 +197,11 @@ Shrinker::ShrinkerResultStatus Shrinker::Run(
       // transformations inapplicable.
       std::vector<uint32_t> next_binary;
       protobufs::TransformationSequence next_transformation_sequence;
-      if (Replayer(impl_->target_env, impl_->validate_during_replay,
-                   impl_->validator_options)
-              .Run(binary_in, initial_facts, transformations_with_chunk_removed,
-                   transformations_with_chunk_removed.transformation_size(),
-                   &next_binary, &next_transformation_sequence) !=
+      if (replayer.Run(
+              binary_in, initial_facts, transformations_with_chunk_removed,
+              static_cast<uint32_t>(
+                  transformations_with_chunk_removed.transformation_size()),
+              &next_binary, &next_transformation_sequence) !=
           Replayer::ReplayerResultStatus::kComplete) {
         // Replay should not fail; if it does, we need to abort shrinking.
         return ShrinkerResultStatus::kReplayFailed;
diff --git a/test/fuzz/fuzzer_shrinker_test.cpp b/test/fuzz/fuzzer_shrinker_test.cpp
index 24b44602e..709e9cef3 100644
--- a/test/fuzz/fuzzer_shrinker_test.cpp
+++ b/test/fuzz/fuzzer_shrinker_test.cpp
@@ -1111,6 +1111,18 @@ TEST(FuzzerShrinkerTest, Miscellaneous3) {
     *temp.mutable_constant_uniform_fact() = resolution_y_eq_100;
     *facts.mutable_fact()->Add() = temp;
   }
+  // Also add an invalid fact, which should be ignored.
+  {
+    protobufs::FactConstantUniform bad_fact;
+    // The descriptor set, binding and indices used here deliberately make no
+    // sense.
+    *bad_fact.mutable_uniform_buffer_element_descriptor() =
+        MakeUniformBufferElementDescriptor(22, 33, {44, 55});
+    *bad_fact.mutable_constant_word()->Add() = 100;
+    protobufs::Fact temp;
+    *temp.mutable_constant_uniform_fact() = bad_fact;
+    *facts.mutable_fact()->Add() = temp;
+  }
 
   // Do 2 fuzzer runs, starting from an initial seed of 194 (seed value chosen
   // arbitrarily).