Index: pythia8313/configure
===================================================================
--- pythia8313.orig/configure
+++ pythia8313/configure
@@ -327,7 +327,7 @@ if [ "$ARCH" != "LINUX" ] && [ "$ARCH" !
     warn "Unknown architecture $ARCH, set as LINUX."; ARCH="LINUX"; fi
 if [ -z "$CXX" ]; then warn "CXX not set, using g++."; CXX="g++"; fi
 if [ -z "$CXX_COMMON" ]; then
-    CXX_COMMON="${ENABLE_DEBUG}-std=c++11 -pedantic -W -Wall -Wshadow -fPIC"
+    CXX_COMMON="${CXXFLAGS} ${ENABLE_DEBUG}-std=c++11 -pedantic -W -Wall -Wshadow -fPIC"
     CXX_COMMON="${CXX_COMMON} -pthread"; fi
 if [ -z "$CXX_SHARED" ]; then
     if [ "$ARCH" = "LINUX" ];  then CXX_SHARED="-shared"; fi