--- a/src/configure.in
+++ b/src/configure.in
@@ -29,7 +29,7 @@ if test -z "$CFLAGS"; then
   test "$GCC" = yes && CFLAGS="-O2 -fno-strength-reduce -Wall"
 fi
 if test "$GCC" = yes; then
-  gccversion=`"$CC" --version | sed -e '2,$d;s/^[[^0-9]]*\(darwin.[[^0-9]]*\)*\([[0-9]]\.[[0-9.]]*\).*$/\2/g'`
+  gccversion=`"$CC" --version | sed -e '2,$d' -e 's/darwin.//' -e 's/^[[^0-9]]*\([[0-9]]\.[[0-9.]]*\).*$/\1/g'`
   dnl version 4.0.1 was reported to cause trouble on Macintosh by Marcin Dalecki
   if test "$gccversion" = "3.0.1" -o "$gccversion" = "3.0.2" -o "$gccversion" = "4.0.1"; then
     echo 'GCC [[34]].0.[[12]] has a bug in the optimizer, disabling "-O#"'
@@ -2834,7 +2834,7 @@ dnl the number before the version number
 AC_MSG_CHECKING(for GCC 3 or later)
 DEPEND_CFLAGS_FILTER=
 if test "$GCC" = yes; then
-  gccmajor=`"$CC" --version | sed -e '2,$d;s/^[[^0-9]]*\(darwin.[[^0-9]]*\)*\([[1-9]]\)\.[[0-9]].*$/\2/g'`
+  gccmajor=`echo "$gccversion" | sed -e 's/^\([[1-9]]\)\..*$/\1/g'`
   if test "$gccmajor" -gt "2"; then
     DEPEND_CFLAGS_FILTER="| sed 's+-I */+-isystem /+g'"
   fi