diff --git a/.gitignore b/.gitignore
index ea47eb3..d452689 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,3 @@
-tests/unittest-cpp
 CMakeFiles
 tests/CMakeFiles
 tests/Debug
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..d9229ae
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "tests/unittest-cpp"]
+	path = tests/unittest-cpp
+	url = https://github.com/Microsoft/unittest-cpp.git
diff --git a/.travis.yml b/.travis.yml
index 3c64230..3fed41b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -56,7 +56,6 @@ install:
 
 before_script:
   - cd ${TRAVIS_BUILD_DIR}
-  - git clone --depth 1 https://github.com/Microsoft/unittest-cpp tests/unittest-cpp
   - cmake -H. -Bb -DCMAKE_CXX_COMPILER=$COMPILER -DCMAKE_INSTALL_PREFIX=$PWD/o -DCMAKE_BUILD_TYPE=$BUILD_TYPE
   - cmake --build b
 
diff --git a/include/gsl_assert.h b/include/gsl_assert.h
index 81cfd13..51e8ab6 100644
--- a/include/gsl_assert.h
+++ b/include/gsl_assert.h
@@ -20,6 +20,7 @@
 #define GSL_CONTRACTS_H
 
 #include <exception>
+#include <stdexcept>
 
 //
 // There are three configuration options for this GSL implementation's behavior
@@ -42,10 +43,6 @@
 // GSL.assert: assertions
 //
 
-#if defined(GSL_THROW_ON_CONTRACT_VIOLATION)
-
-#include <stdexcept>
-
 namespace gsl
 {
 struct fail_fast : public std::runtime_error 
@@ -54,6 +51,8 @@ struct fail_fast : public std::runtime_error
 };
 }
 
+#if defined(GSL_THROW_ON_CONTRACT_VIOLATION)
+
 #define Expects(cond)  if (!(cond)) \
     throw gsl::fail_fast("GSL: Precondition failure at " __FILE__ ": " GSL_STRINGIFY(__LINE__));
 #define Ensures(cond)  if (!(cond)) \
diff --git a/include/gsl_util.h b/include/gsl_util.h
index 508672c..9bb24e3 100644
--- a/include/gsl_util.h
+++ b/include/gsl_util.h
@@ -31,6 +31,9 @@
 #pragma push_macro("constexpr")
 #define constexpr
 
+#pragma warning(push)
+#pragma warning(disable: 4127) // conditional expression is constant
+
 // MSVC 2013 workarounds
 #if _MSC_VER <= 1800
 // noexcept is not understood
@@ -40,7 +43,6 @@
 // turn off some misguided warnings
 #pragma warning(push)
 #pragma warning(disable: 4351) // warns about newly introduced aggregate initializer behavior
-#pragma warning(disable: 4127) // conditional expression is constant
 
 #endif // _MSC_VER <= 1800
 
@@ -132,6 +134,8 @@ constexpr typename Cont::value_type& at(Cont& cont, size_t index)
 
 #ifdef _MSC_VER
 
+#pragma warning(pop)
+
 #undef constexpr
 #pragma pop_macro("constexpr")
 
diff --git a/include/span.h b/include/span.h
index 96164b6..0bffb4b 100644
--- a/include/span.h
+++ b/include/span.h
@@ -31,10 +31,16 @@
 
 #ifdef _MSC_VER
 
-// turn off some warnings that are noisy about our Expects statements
 #pragma warning(push)
+
+// turn off some warnings that are noisy about our Expects statements
 #pragma warning(disable : 4127) // conditional expression is constant
 
+// blanket turn off warnings from CppCoreCheck for now
+// so people aren't annoyed by them when running the tool.
+// more targeted suppressions will be added in a future update to the GSL
+#pragma warning(disable: 26481 26482 26483 26485 26490 26491 26492 26493 26495)
+
 // No MSVC does constexpr fully yet
 #pragma push_macro("constexpr")
 #define constexpr
diff --git a/include/string_span.h b/include/string_span.h
index 8aba362..ccfe251 100644
--- a/include/string_span.h
+++ b/include/string_span.h
@@ -31,6 +31,14 @@
 #pragma push_macro("constexpr")
 #define constexpr /* nothing */
 
+#pragma warning(push)
+
+// blanket turn off warnings from CppCoreCheck for now
+// so people aren't annoyed by them when running the tool.
+// more targeted suppressions will be added in a future update to the GSL
+#pragma warning(disable: 26481 26482 26483 26485 26490 26491 26492 26493 26495)
+
+
 // VS 2013 workarounds
 #if _MSC_VER <= 1800
 
@@ -927,12 +935,14 @@ bool operator>=(const T& one, gsl::basic_string_span<CharT, Extent> other) noexc
 }
 #endif
 
-// VS 2013 workarounds
 #ifdef _MSC_VER
 
+#pragma warning(pop)
+
 #undef constexpr
 #pragma pop_macro("constexpr")
 
+// VS 2013 workarounds
 #if _MSC_VER <= 1800
 
 #ifndef GSL_THROW_ON_CONTRACT_VIOLATION
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 009b52d..79931f7 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -2,6 +2,10 @@ cmake_minimum_required(VERSION 2.8.7)
 
 project(GSLTests CXX)
 
+if (NOT EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/unittest-cpp/tests)
+    execute_process(COMMAND git submodule update --init WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}")
+endif()
+
 add_subdirectory(unittest-cpp)
 
 include_directories(
@@ -28,10 +32,6 @@ else()
     endif()
 endif()
 
-if (NOT EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/unittest-cpp)
-  message(FATAL_ERROR "Could not find unittest-cpp enlistment. Please run 'git clone https://github.com/Microsoft/unittest-cpp.git unittest-cpp' in the tests directory")
-endif()
-
 function(add_gsl_test name)
     add_executable(${name} ${name}.cpp ../include/gsl.h ../include/gsl_assert.h ../include/gsl_util.h ../include/multi_span.h ../include/span.h ../include/string_span.h)
     target_link_libraries(${name} UnitTest++)
diff --git a/tests/unittest-cpp b/tests/unittest-cpp
new file mode 160000
index 0000000..dc6b908
--- /dev/null
+++ b/tests/unittest-cpp
@@ -0,0 +1 @@
+Subproject commit dc6b90838014ab985bf3cd74ac17ad9d00e1fbcb