diff --git a/CMakeLists.txt b/CMakeLists.txt
index f3ccaa4c4..710483709 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -275,11 +275,17 @@ if(EXISTS $ENV{GTEST_DIR})
      set(GTEST_DIR $ENV{GTEST_DIR})
 endif(EXISTS $ENV{GTEST_DIR})
 if(GTEST_DIR)
-     message(STATUS "GTEST root folder at ${GTEST_DIR}")
+     message(STATUS "Googletest root folder set at ${GTEST_DIR}")
+     find_path(LIBGTEST_DEV_DIR NAMES gtest-all.cc PATHS ${GTEST_DIR}/src)
+          if(LIBGTEST_DEV_DIR)
+         message (STATUS "Googletest has been found.")
+     else(LIBGTEST_DEV_DIR)
+         message (FATAL_ERROR " Googletest source code has not been found at ${GTEST_DIR}.")
+     endif(LIBGTEST_DEV_DIR)
 else(GTEST_DIR)
-     find_path(LIBGTEST_DEV_DIR NAMES gtest-all.cc PATHS /usr/src/gtest/src)
+     find_path(LIBGTEST_DEV_DIR NAMES gtest-all.cc PATHS /usr/src/gtest/src /opt/local/src/gtest/src)
      if(LIBGTEST_DEV_DIR)
-         message (STATUS " Googletest (libgtest-dev package) has been found.")
+         message (STATUS "Googletest (libgtest-dev package) has been found.")
      else(LIBGTEST_DEV_DIR)
          message (STATUS " Googletest has not been found.")
          message (STATUS " Googletest will be downloaded and built automatically ")