--- a/configure.ac
+++ b/configure.ac
@@ -2482,7 +2482,7 @@ AC_ARG_ENABLE([pedantic], [AS_HELP_STRING([--enable-pedantic],[enable pedantic c
 if test "z$enable_pedantic" = "zno" ; then
     AC_MSG_RESULT([disabled])
 else
-    CFLAGS="$CFLAGS -O -std=c99 -pedantic -pedantic-errors -W -Wall -Wextra"
+    CFLAGS="$CFLAGS -std=c99 -pedantic -W -Wall -Wextra"
     CFLAGS="$CFLAGS -fno-inline -Wnull-dereference -Wdouble-promotion"
     CFLAGS="$CFLAGS -Wformat=2 -Wformat-security -Wformat-nonliteral"
     CFLAGS="$CFLAGS -Wconversion -Wunused -Wshadow -Wpointer-arith -Wcast-align"