diff --git a/configure.ac b/configure.ac
index a6090e05..2ed6a66a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -16,6 +16,9 @@ AC_PROG_LN_S
 AC_PROG_MAKE_SET
 AC_PROG_INSTALL
 
+dnl For gcc, at lest, use -O3
+PA_ADD_CFLAGS([-O3])
+
 dnl Check for library extension
 PA_LIBEXT