diff --git a/configure.ac b/configure.ac
index 5ecd133..2f29047 100644
--- a/configure.ac
+++ b/configure.ac
@@ -9,6 +9,9 @@
 AM_INIT_AUTOMAKE([dist-bzip2])
 AC_CONFIG_TESTDIR(tests)
 
+CXXFLAGS="$CXXFLAGS -std=gnu++03"
+CFLAGS="$CFLAGS -std=gnu89"
+
 dnl kernel style compile messages
 m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])