diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7b4e527c0..7f8186ddb 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -171,7 +171,7 @@ set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -O2")
 # Googletest - http://code.google.com/p/googletest/
 ################################################################################
 enable_testing()
-set(GTEST_DIR $ENV{GTEST_DIR})
+set(GTEST_DIR "$ENV{GTEST_DIR}")
 if(GTEST_DIR)
      message(STATUS "GTEST root folder at ${GTEST_DIR}")
 else()
diff --git a/src/tests/CMakeLists.txt b/src/tests/CMakeLists.txt
index 9da876e0e..3208ff8c1 100644
--- a/src/tests/CMakeLists.txt
+++ b/src/tests/CMakeLists.txt
@@ -16,10 +16,12 @@
 # along with GNSS-SDR. If not, see <http://www.gnu.org/licenses/>.
 #
 
-set(GTEST_DIR_LOCAL $ENV{GTEST_DIR})
-if(NOT EXISTS GTEST_DIR_LOCAL)
+set(GTEST_DIR_LOCAL "$ENV{GTEST_DIR}")
+if(NOT GTEST_DIR_LOCAL)
     set(GTEST_DIR_LOCAL false)
-endif(NOT EXISTS GTEST_DIR_LOCAL)
+else()
+	set(GTEST_DIR_LOCAL true)
+endif(NOT GTEST_DIR_LOCAL)
 
 
 if(NOT GTEST_DIR_LOCAL)
diff --git a/src/tests/arithmetic/multiply_test.cc b/src/tests/arithmetic/multiply_test.cc
index be45ee25a..eb0d16f4f 100644
--- a/src/tests/arithmetic/multiply_test.cc
+++ b/src/tests/arithmetic/multiply_test.cc
@@ -89,7 +89,7 @@ TEST(Multiply_Test, ArmadilloImplementation)
               << "-length double Armadillo vectors finished in " << (end - begin)
               << " microseconds" << std::endl;
     ASSERT_LE(0, end - begin);
-    ASSERT_EQ(0, arma::norm(output));
+    ASSERT_EQ(0, arma::norm(output,2));
 }
 
 
@@ -173,7 +173,7 @@ TEST(Multiply_Test, ArmadilloComplexImplementation)
               << "-length complex float Armadillo vectors finished in " << (end - begin)
               << " microseconds" << std::endl;
     ASSERT_LE(0, end - begin);
-    ASSERT_EQ(0, arma::norm(output));
+    ASSERT_EQ(0, arma::norm(output,2));
 }