diff --git a/configure.ac b/configure.ac
index 62a4284719..b0ae5f349d 100755
--- a/configure.ac
+++ b/configure.ac
@@ -20,7 +20,9 @@ AC_CANONICAL_BUILD()
 AC_CANONICAL_HOST()
 AC_CANONICAL_TARGET()
 
-AM_INIT_AUTOMAKE(1.6)
+# Disable portability warnings -- our automake code (in particular
+# common.am) uses some constructs specific to gmake.
+AM_INIT_AUTOMAKE([1.6 -Wno-portability])
 m4_ifndef([AM_SILENT_RULES], [m4_define([AM_SILENT_RULES],[])])
 AM_SILENT_RULES([yes])
 AC_CONFIG_HEADERS(config.h)