diff --git a/UnitTest++/Config.h b/UnitTest++/Config.h
index 5313b09..4f695f7 100644
--- a/UnitTest++/Config.h
+++ b/UnitTest++/Config.h
@@ -7,7 +7,8 @@
 	#pragma warning(disable:4702) // unreachable code
 	#pragma warning(disable:4722) // destructor never returns, potential memory leak
 
-	#if (_MSC_VER == 1200)  // VC6
+#if (_MSC_VER == 1200)  // VC6
+		#define UNITTEST_COMPILER_IS_MSVC6
 		#pragma warning(disable:4786)
 		#pragma warning(disable:4290)
 	#endif
@@ -60,4 +61,13 @@
 
 //#define UNITTEST_NO_EXCEPTIONS
 
+
+// std namespace qualification: used for functions like strcpy that 
+// may live in std:: namespace (cstring header).
+#if defined( UNITTEST_COMPILER_IS_MSVC6 )
+	#define UNIITEST_NS_QUAL_STD(x) x
+#else
+	#define UNIITEST_NS_QUAL_STD(x) ::std::x
+#endif
+
 #endif
diff --git a/UnitTest++/DeferredTestResult.cpp b/UnitTest++/DeferredTestResult.cpp
index 5071f82..cdad9eb 100644
--- a/UnitTest++/DeferredTestResult.cpp
+++ b/UnitTest++/DeferredTestResult.cpp
@@ -16,7 +16,7 @@ DeferredTestFailure::DeferredTestFailure()
 DeferredTestFailure::DeferredTestFailure(int lineNumber_, const char* failureStr_)
 	: lineNumber(lineNumber_)
 {
-	std::strcpy(failureStr, failureStr_);
+	UNIITEST_NS_QUAL_STD(strcpy)(failureStr, failureStr_);
 }
 
 DeferredTestResult::DeferredTestResult()
diff --git a/UnitTest++/HelperMacros.h b/UnitTest++/HelperMacros.h
index fb3181d..699d99d 100644
--- a/UnitTest++/HelperMacros.h
+++ b/UnitTest++/HelperMacros.h
@@ -5,7 +5,7 @@
 
 #define UNITTEST_MULTILINE_MACRO_BEGIN do {
 
-#ifdef UNITTEST_WIN32
+#if defined(UNITTEST_WIN32) && !defined(UNITTEST_COMPILER_IS_MSVC6)
 	#define UNITTEST_MULTILINE_MACRO_END \
 		} __pragma(warning(push)) __pragma(warning(disable:4127)) while (0) __pragma(warning(pop))
 #else
diff --git a/UnitTest++/MemoryOutStream.cpp b/UnitTest++/MemoryOutStream.cpp
index 3c112b6..319dfda 100644
--- a/UnitTest++/MemoryOutStream.cpp
+++ b/UnitTest++/MemoryOutStream.cpp
@@ -16,6 +16,33 @@ void MemoryOutStream::Clear()
 	m_text = this->str();
 }
 
+#ifdef UNITTEST_COMPILER_IS_MSVC6
+
+#define snprintf _snprintf
+
+template<typename ValueType>
+std::ostream& FormatToStream(std::ostream& stream, char const* format, ValueType const& value)
+{
+   using namespace std;
+   
+   const size_t BUFFER_SIZE=32;
+   char txt[BUFFER_SIZE];
+   snprintf(txt, BUFFER_SIZE, format, value);
+   return stream << txt;
+}
+
+std::ostream& operator<<(std::ostream& stream, __int64 const n)
+{
+   return FormatToStream(stream, "%I64d", n);
+}
+
+std::ostream& operator<<(std::ostream& stream, unsigned __int64 const n)
+{
+   return FormatToStream(stream, "%I64u", n);
+}
+
+#endif
+
 }
 
 #else
@@ -108,7 +135,11 @@ MemoryOutStream& MemoryOutStream::operator <<(unsigned long const n)
     return *this;
 }
 
+#ifdef UNITTEST_COMPILER_IS_MSVC6
+MemoryOutStream& MemoryOutStream::operator <<(__int64 const n)
+#else
 MemoryOutStream& MemoryOutStream::operator <<(long long const n)
+#endif
 {
 #ifdef UNITTEST_WIN32
 	FormatToStream(*this, "%I64d", n);
@@ -119,7 +150,11 @@ MemoryOutStream& MemoryOutStream::operator <<(long long const n)
 	return *this;
 }
 
+#ifdef UNITTEST_COMPILER_IS_MSVC6
+MemoryOutStream& MemoryOutStream::operator <<(unsigned __int64 const n)
+#else
 MemoryOutStream& MemoryOutStream::operator <<(unsigned long long const n)
+#endif
 {
 #ifdef UNITTEST_WIN32
 	FormatToStream(*this, "%I64u", n);
diff --git a/UnitTest++/MemoryOutStream.h b/UnitTest++/MemoryOutStream.h
index 0c46f53..b9cea19 100644
--- a/UnitTest++/MemoryOutStream.h
+++ b/UnitTest++/MemoryOutStream.h
@@ -26,12 +26,21 @@ class UNITTEST_LINKAGE MemoryOutStream : public std::ostringstream
     mutable std::string m_text;
 };
 
+#ifdef UNITTEST_COMPILER_IS_MSVC6
+std::ostream& operator<<(std::ostream& stream, __int64 const n);
+std::ostream& operator<<(std::ostream& stream, unsigned __int64 const n);
+#endif
+
 }
 
 #else
 
 #include <cstddef>
 
+#ifdef UNITTEST_COMPILER_IS_MSVC6
+namespace std {}
+#endif
+
 namespace UnitTest
 {
 
@@ -47,10 +56,15 @@ class UNITTEST_LINKAGE MemoryOutStream
     MemoryOutStream& operator <<(char const* txt);
     MemoryOutStream& operator <<(int n);
     MemoryOutStream& operator <<(long n);
-	MemoryOutStream& operator <<(long long n);
     MemoryOutStream& operator <<(unsigned long n);
-	MemoryOutStream& operator <<(unsigned long long n);
-    MemoryOutStream& operator <<(float f);
+#ifdef UNITTEST_COMPILER_IS_MSVC6
+    MemoryOutStream& operator <<(__int64 n);
+    MemoryOutStream& operator <<(unsigned __int64 n);
+#else
+    MemoryOutStream& operator <<(long long n);
+    MemoryOutStream& operator <<(unsigned long long n);
+#endif
+   MemoryOutStream& operator <<(float f);
     MemoryOutStream& operator <<(double d);
     MemoryOutStream& operator <<(void const* p);
     MemoryOutStream& operator <<(unsigned int s);
diff --git a/tests/TestChecks.cpp b/tests/TestChecks.cpp
index 758ca31..9554b31 100644
--- a/tests/TestChecks.cpp
+++ b/tests/TestChecks.cpp
@@ -150,7 +150,7 @@ TEST(CheckCloseWithNaNFails)
 {
 	const unsigned int bitpattern = 0xFFFFFFFF;
 	float nan;
-	std::memcpy(&nan, &bitpattern, sizeof(bitpattern));
+	UNIITEST_NS_QUAL_STD(memcpy)(&nan, &bitpattern, sizeof(bitpattern));
 
 	TestResults results;
     CheckClose(results, 3.0f, nan, 0.1f, TestDetails("", "", "", 0));
@@ -161,7 +161,7 @@ TEST(CheckCloseWithNaNAgainstItselfFails)
 {
 	const unsigned int bitpattern = 0xFFFFFFFF;
 	float nan;
-	std::memcpy(&nan, &bitpattern, sizeof(bitpattern));
+	UNIITEST_NS_QUAL_STD(memcpy)(&nan, &bitpattern, sizeof(bitpattern));
 
     TestResults results;
     CheckClose(results, nan, nan, 0.1f, TestDetails("", "", "", 0));
diff --git a/tests/TestMemoryOutStream.cpp b/tests/TestMemoryOutStream.cpp
index 74a9a56..ff1e920 100644
--- a/tests/TestMemoryOutStream.cpp
+++ b/tests/TestMemoryOutStream.cpp
@@ -170,8 +170,12 @@ TEST(StreamingMinUnsignedLongWritesCorrectCharacters)
 TEST(StreamingLongLongWritesCorrectCharacters)
 {
 	MemoryOutStream stream;
+#ifdef UNITTEST_COMPILER_IS_MSVC6
+   stream << (__int64)-12345i64;
+#else
 	stream << (long long)-12345ll;
-	CHECK_EQUAL("-12345", stream.GetText());
+#endif
+   CHECK_EQUAL("-12345", stream.GetText());
 }
 
 #ifdef LLONG_MAX
@@ -195,8 +199,12 @@ TEST(StreamingMinLongLongWritesCorrectCharacters)
 TEST(StreamingUnsignedLongLongWritesCorrectCharacters)
 {
 	MemoryOutStream stream;
-	stream << (unsigned long long)85899ull;
-	CHECK_EQUAL("85899", stream.GetText());
+#ifdef UNITTEST_COMPILER_IS_MSVC6
+   stream << (unsigned __int64)85899ui64;
+#else
+   stream << (unsigned long long)85899ull;
+#endif
+   CHECK_EQUAL("85899", stream.GetText());
 }
 
 #ifdef ULLONG_MAX
@@ -211,7 +219,11 @@ TEST(StreamingMaxUnsignedLongLongWritesCorrectCharacters)
 TEST(StreamingMinUnsignedLongLongWritesCorrectCharacters)
 {
     MemoryOutStream stream;
+#ifdef UNITTEST_COMPILER_IS_MSVC6
+    stream << (unsigned __int64)0ui64;
+#else
     stream << (unsigned long long)0ull;
+#endif
     CHECK_EQUAL("0", stream.GetText());
 }