diff --git a/src/tests/kits/shared/JsonEndToEndTest.cpp b/src/tests/kits/shared/JsonEndToEndTest.cpp
index 061504b391..4f7d9fe6bb 100644
--- a/src/tests/kits/shared/JsonEndToEndTest.cpp
+++ b/src/tests/kits/shared/JsonEndToEndTest.cpp
@@ -29,7 +29,7 @@ JsonEndToEndTest::~JsonEndToEndTest()
 
 
 void
-JsonEndToEndTest::TestParseAndWrite(char* input, char* expectedOutput)
+JsonEndToEndTest::TestParseAndWrite(const char* input, const char* expectedOutput)
 {
 	BDataIO* inputData = new BMemoryIO(input, strlen(input));
 	ObjectDeleter<BDataIO> inputDataDeleter(inputData);
diff --git a/src/tests/kits/shared/JsonEndToEndTest.h b/src/tests/kits/shared/JsonEndToEndTest.h
index 07b9712cb3..cd536482c5 100644
--- a/src/tests/kits/shared/JsonEndToEndTest.h
+++ b/src/tests/kits/shared/JsonEndToEndTest.h
@@ -37,8 +37,8 @@ public:
 private:
 			void				TestUnterminated(const char* input);
 
-			void				TestParseAndWrite(char* input,
-									char* expectedOutput);
+			void				TestParseAndWrite(const char* input,
+									const char* expectedOutput);
 };
 
 
diff --git a/src/tests/kits/shared/JsonErrorHandlingTest.cpp b/src/tests/kits/shared/JsonErrorHandlingTest.cpp
index 6c54e383a8..1e97505b89 100644
--- a/src/tests/kits/shared/JsonErrorHandlingTest.cpp
+++ b/src/tests/kits/shared/JsonErrorHandlingTest.cpp
@@ -301,12 +301,8 @@ JsonErrorHandlingTest::TestBadStringEscape()
 void
 JsonErrorHandlingTest::TestBadNumber()
 {
-	BString expectedMessage;
-	expectedMessage.SetToFormat("malformed number",
-		JSON_SAMPLE_BROKEN_NUMBER);
-
 	TestParseWithErrorMessage(JSON_SAMPLE_BROKEN_NUMBER, 1, B_BAD_DATA,
-		expectedMessage.String());
+		"malformed number");
 }
 
 
diff --git a/src/tests/kits/shared/JsonTextWriterTest.cpp b/src/tests/kits/shared/JsonTextWriterTest.cpp
index 99b427f118..91585f9fe2 100644
--- a/src/tests/kits/shared/JsonTextWriterTest.cpp
+++ b/src/tests/kits/shared/JsonTextWriterTest.cpp
@@ -111,7 +111,7 @@ JsonTextWriterTest::TestInteger()
 	BMallocIO* outputData = new BMallocIO();
 	ObjectDeleter<BMallocIO> outputDataDeleter(outputData);
 	BJsonTextWriter writer(outputData);
-	static char* expectedOut = JSON_SAMPLE_NUMBER_B_EXPECTED_OUT;
+	static const char* expectedOut = JSON_SAMPLE_NUMBER_B_EXPECTED_OUT;
 
 	CPPUNIT_ASSERT_EQUAL(B_OK,
 		writer.WriteInteger(JSON_SAMPLE_NUMBER_B_LITERAL));
@@ -134,7 +134,7 @@ JsonTextWriterTest::TestDouble()
 	BMallocIO* outputData = new BMallocIO();
 	ObjectDeleter<BMallocIO> outputDataDeleter(outputData);
 	BJsonTextWriter writer(outputData);
-	static char* expectedOut = "3.142857";
+	static const char* expectedOut = "3.142857";
 
 	CPPUNIT_ASSERT_EQUAL(B_OK,
 		writer.WriteDouble(JSON_SAMPLE_NUMBER_A_LITERAL));
@@ -157,7 +157,7 @@ JsonTextWriterTest::TestFalse()
 	BMallocIO* outputData = new BMallocIO();
 	ObjectDeleter<BMallocIO> outputDataDeleter(outputData);
 	BJsonTextWriter writer(outputData);
-	static char* expectedOut = "false";
+	static const char* expectedOut = "false";
 
 	CPPUNIT_ASSERT_EQUAL(B_OK, writer.WriteFalse());
 	writer.Complete();
diff --git a/src/tests/kits/shared/JsonToMessageTest.cpp b/src/tests/kits/shared/JsonToMessageTest.cpp
index 9e15371d5c..e257fb485d 100644
--- a/src/tests/kits/shared/JsonToMessageTest.cpp
+++ b/src/tests/kits/shared/JsonToMessageTest.cpp
@@ -1,4 +1,4 @@
-	/*
+/*
  * Copyright 2017, Andrew Lindesay <apl@lindesay.co.nz>
  * Distributed under the terms of the MIT License.
  */