diff --git a/CMakeLists.txt b/CMakeLists.txt
index a1d6ea349..a79bac21e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -419,7 +419,14 @@ if(OS_IS_MACOSX)
     endif(CMAKE_GENERATOR STREQUAL Xcode)
 endif(OS_IS_MACOSX)
 if(NOT VOLK_GNSSSDR_FOUND)
-    set(VOLK_GNSSSDR_CMAKE_ARGS -DCMAKE_C_COMPILER=${CMAKE_C_COMPILER} -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER} -DCMAKE_INSTALL_PREFIX=${CMAKE_CURRENT_BINARY_DIR}/volk_gnsssdr_module/install -DENABLE_STATIC_LIBS=ON ${STRIP_VOLK_GNSSSDR_PROFILE} ${USE_THIS_PYTHON})
+    set(VOLK_GNSSSDR_CMAKE_ARGS -DCMAKE_C_COMPILER=${CMAKE_C_COMPILER}
+                                -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
+                                -DCMAKE_INSTALL_PREFIX=${CMAKE_CURRENT_BINARY_DIR}/volk_gnsssdr_module/install
+                                -DENABLE_STATIC_LIBS=ON
+                                -DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS}
+                                -DCMAKE_C_FLAGS=${CMAKE_C_FLAGS}
+                                ${STRIP_VOLK_GNSSSDR_PROFILE} 
+                                ${USE_THIS_PYTHON} )
     if(CMAKE_TOOLCHAIN_FILE)
         set(VOLK_GNSSSDR_CMAKE_ARGS ${VOLK_GNSSSDR_CMAKE_ARGS} -DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE})
     endif(CMAKE_TOOLCHAIN_FILE)
diff --git a/src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr/lib/CMakeLists.txt b/src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr/lib/CMakeLists.txt
index 99852beb0..62cdb5da8 100644
--- a/src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr/lib/CMakeLists.txt
+++ b/src/algorithms/libs/volk_gnsssdr_module/volk_gnsssdr/lib/CMakeLists.txt
@@ -79,6 +79,10 @@ if(HAVE_POSIX_MEMALIGN)
       add_definitions(-DHAVE_POSIX_MEMALIGN)
 endif(HAVE_POSIX_MEMALIGN)
 
+if(NOT DEFINED _XOPEN_SOURCE)
+      add_definitions(-D_XOPEN_SOURCE=700)
+endif(NOT DEFINED _XOPEN_SOURCE)
+
 ########################################################################
 # detect x86 flavor of CPU
 ########################################################################