diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
index 4692372cec..14ec5059f1 100644
--- a/cmake/CMakeLists.txt
+++ b/cmake/CMakeLists.txt
@@ -2,6 +2,7 @@ cmake_minimum_required(VERSION 3.1)
 
 project(lammps)
 set(SOVERSION 0)
+set(LAMMPS_SOURCE_DIR ${CMAKE_SOURCE_DIR}/../src)
 
 if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_C_FLAGS)
   #release comes with -O3 by default
@@ -29,8 +30,8 @@ if(ENABLE_MPI)
   include_directories(${MPI_C_INCLUDE_PATH})
   set(MPI_SOURCES)
 else()
-  file(GLOB MPI_SOURCES ${CMAKE_SOURCE_DIR}/../src/STUBS/mpi.c)
-  include_directories(${CMAKE_SOURCE_DIR}/../src/STUBS)
+  file(GLOB MPI_SOURCES ${LAMMPS_SOURCE_DIR}/STUBS/mpi.c)
+  include_directories(${LAMMPS_SOURCE_DIR}/STUBS)
   set(MPI_CXX_LIBRARIES)
 endif()
 
@@ -87,15 +88,15 @@ endforeach(FUNC)
 #Do NOT go into src to not conflict with old Makefile build system
 #add_subdirectory(src)
 
-file(GLOB LIB_SOURCES ${CMAKE_SOURCE_DIR}/../src/*.cpp)
-file(GLOB LMP_SOURCES ${CMAKE_SOURCE_DIR}/../src/main.cpp)
+file(GLOB LIB_SOURCES ${LAMMPS_SOURCE_DIR}/*.cpp)
+file(GLOB LMP_SOURCES ${LAMMPS_SOURCE_DIR}/main.cpp)
 list(REMOVE_ITEM LIB_SOURCES ${LMP_SOURCES})
 
 foreach(PKG ${PACKAGES})
   if(ENABLE_${PKG})
-    file(GLOB ${PKG}_SOURCES ${CMAKE_SOURCE_DIR}/../src/${PKG}/*.cpp)
+    file(GLOB ${PKG}_SOURCES ${LAMMPS_SOURCE_DIR}/${PKG}/*.cpp)
     list(APPEND LIB_SOURCES ${${PKG}_SOURCES})
-    include_directories(${CMAKE_SOURCE_DIR}/../src/${PKG})
+    include_directories(${LAMMPS_SOURCE_DIR}/${PKG})
   endif()
 endforeach()
 
@@ -105,7 +106,7 @@ if(ENABLE_REAX)
   list(APPEND LIB_SOURCES ${REAX_SOURCES})
   include_directories(${CMAKE_SOURCE_DIR}/../lib/reax)
 endif()
-include_directories(${CMAKE_SOURCE_DIR}/../src)
+include_directories(${LAMMPS_SOURCE_DIR})
 include_directories(${CMAKE_SOURCE_DIR}/Headers)
 configure_file(${CMAKE_SOURCE_DIR}/Headers/package.h.cmakein ${CMAKE_BINARY_DIR}/cmake/package.h)
 include_directories(${CMAKE_BINARY_DIR}/cmake)