diff --git a/mediapipe/calculators/core/mux_calculator_test.cc b/mediapipe/calculators/core/mux_calculator_test.cc
index 86d2fab42..a3ac8a27a 100644
--- a/mediapipe/calculators/core/mux_calculator_test.cc
+++ b/mediapipe/calculators/core/mux_calculator_test.cc
@@ -398,6 +398,99 @@ TEST(MuxCalculatorTest, HandleTimestampBoundUpdates) {
   MP_ASSERT_OK(graph.WaitUntilDone());
 }
 
+TEST(MuxCalculatorTest, HandlesCloseGracefully) {
+  CalculatorGraphConfig config =
+      mediapipe::ParseTextProtoOrDie<CalculatorGraphConfig>(
+          R"pb(
+            input_stream: "select"
+            input_stream: "value_0"
+            input_stream: "value_1"
+            node {
+              calculator: "MuxCalculator"
+              input_stream: "SELECT:select"
+              input_stream: "INPUT:0:value_0"
+              input_stream: "INPUT:1:value_1"
+              output_stream: "OUTPUT:output"
+            }
+          )pb");
+  CalculatorGraph graph;
+  MP_ASSERT_OK(graph.Initialize(config));
+
+  // Observe packets.
+  std::vector<Packet> output_packets;
+  MP_ASSERT_OK(graph.ObserveOutputStream(
+      "output",
+      [&output_packets](const Packet& p) -> absl::Status {
+        output_packets.push_back(p);
+        return absl::OkStatus();
+      },
+      /*observe_timestamp_bounds=*/true));
+
+  // Start graph.
+  MP_ASSERT_OK(graph.StartRun({}));
+
+  // Add single packet wait for completion and close.
+  MP_ASSERT_OK(graph.AddPacketToInputStream(
+      "value_0", MakePacket<int>(0).At(Timestamp(1000))));
+  MP_ASSERT_OK(graph.WaitUntilIdle());
+  MP_ASSERT_OK(graph.CloseAllInputStreams());
+  MP_ASSERT_OK(graph.WaitUntilDone());
+
+  EXPECT_TRUE(output_packets.empty());
+}
+
+TEST(MuxCalculatorTest, CrashesOnCloseWithDeafultInputStreamHandler) {
+  CalculatorGraphConfig config =
+      mediapipe::ParseTextProtoOrDie<CalculatorGraphConfig>(
+          R"pb(
+            # This is required in order for EXPECT_DEATH to work everywhere
+            executor { name: "" type: "ApplicationThreadExecutor" }
+
+            input_stream: "select"
+            input_stream: "value_0"
+            input_stream: "value_1"
+            node {
+              calculator: "MuxCalculator"
+              input_stream: "SELECT:select"
+              input_stream: "INPUT:0:value_0"
+              input_stream: "INPUT:1:value_1"
+              output_stream: "OUTPUT:output"
+              input_stream_handler {
+                input_stream_handler: "DefaultInputStreamHandler"
+              }
+            }
+          )pb");
+  CalculatorGraph graph;
+  MP_ASSERT_OK(graph.Initialize(config));
+
+  // Observe packets.
+  std::vector<Packet> output_packets;
+  MP_ASSERT_OK(graph.ObserveOutputStream(
+      "output",
+      [&output_packets](const Packet& p) -> absl::Status {
+        output_packets.push_back(p);
+        return absl::OkStatus();
+      },
+      /*observe_timestamp_bounds=*/true));
+
+  // Start graph.
+  MP_ASSERT_OK(graph.StartRun({}));
+
+  // Add single packet wait for completion and close.
+  MP_ASSERT_OK(graph.AddPacketToInputStream(
+      "value_0", MakePacket<int>(0).At(Timestamp(1000))));
+  MP_ASSERT_OK(graph.WaitUntilIdle());
+  // Currently MuxCalculator crashes with a correct packet set from
+  // DefaultInputStreamHandler.  The SELECT packet is missing at Timestamp 1000,
+  // and an empty packet is the correct representation of that.
+  EXPECT_DEATH(
+      {
+        (void)graph.CloseAllInputStreams();
+        (void)graph.WaitUntilDone();
+      },
+      "Check failed: payload_");
+}
+
 }  // namespace
 
 }  // namespace mediapipe