diff --git a/install.sh b/install.sh
index 10f8211..52b6044 100755
--- a/install.sh
+++ b/install.sh
@@ -40,11 +40,14 @@ case `uname` in
         export DARWIN=0
         GCC_VERSION=`gcc -dumpversion`
         COMPILER_NAME="gcc $GCC_VERSION"
-        if [ "$GCC_VERSION" \> "4.6.0" ] || [ "$GCC_VERSION" = "4.6.0" ] || [ "$GCC_VERSION" = "4.6" ] || [ "$GCC_VERSION" -ge 5 ]; then
+        if [ "${GCC_VERSION%%.*}" -ge 5 ]; then
+           export USE_AVX=yes
+           export USE_AVX2=yes
+        elif [ "$GCC_VERSION" \> "4.7.0" ] || [ "$GCC_VERSION" = "4.7.0" ] || [ "$GCC_VERSION" = "4.7" ] || [ "$GCC_VERSION" -ge 5 ]; then
            export USE_AVX=yes
-        fi
-        if [ "$GCC_VERSION" \> "4.7.0" ] || [ "$GCC_VERSION" = "4.7.0" ] || [ "$GCC_VERSION" = "4.7" ] || [ "$GCC_VERSION" -ge 5 ]; then
            export USE_AVX2=yes
+        elif [ "$GCC_VERSION" \> "4.6.0" ] || [ "$GCC_VERSION" = "4.6.0" ] || [ "$GCC_VERSION" = "4.6" ] || [ "$GCC_VERSION" -ge 5 ]; then
+           export USE_AVX=yes
         fi
         ;;
 esac