diff --git a/cmake_modules/FindProtobuf.cmake b/cmake_modules/FindProtobuf.cmake
index 6be08638..4b91a1d3 100644
--- a/cmake_modules/FindProtobuf.cmake
+++ b/cmake_modules/FindProtobuf.cmake
@@ -1,7 +1,7 @@
 # Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
 # file Copyright.txt or https://cmake.org/licensing for details.
 
-set(LIBRARY_ROOT "${LIBRARY_REPOSITORY_ROOT}/protobuf")
+set(LIBRARY_ROOT "${CXX_COMMON_REPOSITORY_ROOT}/protobuf")
 
 set(Protobuf_FOUND TRUE)
 set(Protobuf_INCLUDE_DIR "${LIBRARY_ROOT}/include")
diff --git a/cmake_modules/FindXED.cmake b/cmake_modules/FindXED.cmake
index 4f336b73..b9650291 100644
--- a/cmake_modules/FindXED.cmake
+++ b/cmake_modules/FindXED.cmake
@@ -1,4 +1,4 @@
-set(LIBRARY_ROOT "${LIBRARY_REPOSITORY_ROOT}/xed")
+set(LIBRARY_ROOT "${CXX_COMMON_REPOSITORY_ROOT}/xed")
 
 set(XED_FOUND TRUE)
 set(XED_INCLUDE_DIRS "${LIBRARY_ROOT}/include")
diff --git a/cmake_modules/Findcapstone.cmake b/cmake_modules/Findcapstone.cmake
index 622e3308..4c4b9b3c 100644
--- a/cmake_modules/Findcapstone.cmake
+++ b/cmake_modules/Findcapstone.cmake
@@ -1,4 +1,4 @@
-set(LIBRARY_ROOT "${LIBRARY_REPOSITORY_ROOT}/capstone")
+set(LIBRARY_ROOT "${CXX_COMMON_REPOSITORY_ROOT}/capstone")
 
 set(CAPSTONE_FOUND TRUE)
 set(CAPSTONE_INCLUDE_DIRS "${LIBRARY_ROOT}/include")
diff --git a/cmake_modules/Finddrdecode.cmake b/cmake_modules/Finddrdecode.cmake
index a12eb198..78da0540 100644
--- a/cmake_modules/Finddrdecode.cmake
+++ b/cmake_modules/Finddrdecode.cmake
@@ -1,4 +1,4 @@
-set(LIBRARY_ROOT "${LIBRARY_REPOSITORY_ROOT}/drdecode")
+set(LIBRARY_ROOT "${CXX_COMMON_REPOSITORY_ROOT}/drdecode")
 
 set(DRDECODE_FOUND TRUE)
 set(DRDECODE_INCLUDE_DIRS "${LIBRARY_ROOT}/include")
diff --git a/cmake_modules/Findgtest.cmake b/cmake_modules/Findgtest.cmake
index c882d9ad..d0f6f71d 100644
--- a/cmake_modules/Findgtest.cmake
+++ b/cmake_modules/Findgtest.cmake
@@ -1,4 +1,4 @@
-set(LIBRARY_ROOT "${LIBRARY_REPOSITORY_ROOT}/googletest")
+set(LIBRARY_ROOT "${CXX_COMMON_REPOSITORY_ROOT}/googletest")
 
 set(gtest_FOUND TRUE)
 set(gtest_INCLUDE_DIRS "${LIBRARY_ROOT}/include")
diff --git a/cmake_modules/repository.cmake b/cmake_modules/repository.cmake
index 131e2cf2..be9e4648 100644
--- a/cmake_modules/repository.cmake
+++ b/cmake_modules/repository.cmake
@@ -1,15 +1,19 @@
-set(LIBRARY_REPOSITORY_ROOT $ENV{TRAILOFBITS_LIBRARIES})
+if(DEFINED ENV{TRAILOFBITS_LIBRARIES})
+  set(CXX_COMMON_REPOSITORY_ROOT $ENV{TRAILOFBITS_LIBRARIES} CACHE PATH "Location of cxx-common libraries")
+endif()
 
-if ("${LIBRARY_REPOSITORY_ROOT}" STREQUAL "")
+if("x${CXX_COMMON_REPOSITORY_ROOT}x" STREQUAL "xx")
     message(ERROR "The TRAILOFBITS_LIBRARIES environment variable is not defined!")
-endif ()
+endif()
 
-list(APPEND CMAKE_MODULE_PATH "${LIBRARY_REPOSITORY_ROOT}/cmake_modules")
+list(APPEND CMAKE_MODULE_PATH "${CXX_COMMON_REPOSITORY_ROOT}/cmake_modules")
 
-list(APPEND CMAKE_PREFIX_PATH "${LIBRARY_REPOSITORY_ROOT}/gflags")
-list(APPEND CMAKE_PREFIX_PATH "${LIBRARY_REPOSITORY_ROOT}/llvm")
-list(APPEND CMAKE_PREFIX_PATH "${LIBRARY_REPOSITORY_ROOT}/glog")
-list(APPEND CMAKE_PREFIX_PATH "${LIBRARY_REPOSITORY_ROOT}/protobuf/lib/cmake/protobuf")
-list(APPEND CMAKE_PREFIX_PATH "${LIBRARY_REPOSITORY_ROOT}/capnproto/lib/cmake/CapnProto")
-set(BOOST_ROOT "${LIBRARY_REPOSITORY_ROOT}/boost")
+list(APPEND CMAKE_PREFIX_PATH "${CXX_COMMON_REPOSITORY_ROOT}/gflags")
+list(APPEND CMAKE_PREFIX_PATH "${CXX_COMMON_REPOSITORY_ROOT}/llvm")
+list(APPEND CMAKE_PREFIX_PATH "${CXX_COMMON_REPOSITORY_ROOT}/glog")
+list(APPEND CMAKE_PREFIX_PATH "${CXX_COMMON_REPOSITORY_ROOT}/protobuf/lib/cmake/protobuf")
+list(APPEND CMAKE_PREFIX_PATH "${CXX_COMMON_REPOSITORY_ROOT}/capnproto/lib/cmake/CapnProto")
 
+if(EXISTS "${CXX_COMMON_REPOSITORY_ROOT}/boost")
+  set(BOOST_ROOT "${CXX_COMMON_REPOSITORY_ROOT}/boost")
+endif()