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/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 7990ec3..e6527da 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} ${name}.cpp ../include/gsl.h ../include/gsl_assert.h ../include/gsl_util.h ../include/span.h ../include/string_span.h)
     target_link_libraries(${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