diff --git a/OSBindings/Mac/Clock SignalTests/ArrayBuilderTests.mm b/OSBindings/Mac/Clock SignalTests/ArrayBuilderTests.mm
index 983feca4b..ce7ce159c 100644
--- a/OSBindings/Mac/Clock SignalTests/ArrayBuilderTests.mm	
+++ b/OSBindings/Mac/Clock SignalTests/ArrayBuilderTests.mm	
@@ -30,8 +30,8 @@ static void setData(bool is_input, uint8_t *data, size_t size)
 	XCTAssert(inputData != nil, @"Should have received some input data");
 	XCTAssert(outputData != nil, @"Should have received some output data");
 
-	XCTAssert(inputData.length == inputSize, @"Input data should be 5 bytes long, was %d", inputData.length);
-	XCTAssert(outputData.length == outputSize, @"Output data should be 3 bytes long, was %d", outputData.length);
+	XCTAssert(inputData.length == inputSize, @"Input data should be 5 bytes long, was %lu", (unsigned long)inputData.length);
+	XCTAssert(outputData.length == outputSize, @"Output data should be 3 bytes long, was %lu", (unsigned long)outputData.length);
 
 	uint8_t *input = (uint8_t *)inputData.bytes;
 	uint8_t *output = (uint8_t *)outputData.bytes;
@@ -80,4 +80,26 @@ static void setData(bool is_input, uint8_t *data, size_t size)
 	[self assertMonotonicForInputSize:4 outputSize:4];
 }
 
+- (void)testSubmitWithoutFlush
+{
+	Outputs::CRT::ArrayBuilder arrayBuilder(200, 100, setData);
+
+	arrayBuilder.get_input_storage(5);
+	arrayBuilder.get_input_storage(8);
+	arrayBuilder.get_output_storage(6);
+	arrayBuilder.get_input_storage(12);
+	arrayBuilder.get_output_storage(3);
+
+	arrayBuilder.submit();
+
+	XCTAssert(inputData.length == 0, @"No input data should have been received; %lu bytes were received", (unsigned long)inputData.length);
+	XCTAssert(outputData.length == 0, @"No output data should have been received; %lu bytes were received", (unsigned long)outputData.length);
+
+	arrayBuilder.flush();
+	arrayBuilder.submit();
+
+	XCTAssert(inputData.length == 25, @"All input data should have been received; %lu bytes were received", (unsigned long)inputData.length);
+	XCTAssert(outputData.length == 9, @"All output data should have been received; %lu bytes were received", (unsigned long)outputData.length);
+}
+
 @end