diff --git a/m4/curl-compilers.m4 b/m4/curl-compilers.m4
index 0fde2f9455..3890d536c4 100644
--- a/m4/curl-compilers.m4
+++ b/m4/curl-compilers.m4
@@ -185,7 +185,7 @@ AC_DEFUN([CURL_CHECK_COMPILER_GNU_C], [
     compiler_id="GNU_C"
     AC_MSG_CHECKING([compiler version])
     # strip '-suffix' parts, e.g. Ubuntu Windows cross-gcc returns '10-win32'
-    gccver=`$CC -dumpversion | sed -E 's/-.+$//'`
+    gccver=`$CC -dumpversion | "$SED" 's/-.\{1,\}$//'`
     gccvhi=`echo $gccver | cut -d . -f1`
     if echo $gccver | grep -F '.' >/dev/null; then
       gccvlo=`echo $gccver | cut -d . -f2`