diff --git a/configure.ac b/configure.ac
index d36b580..8d92a3d 100755
--- a/configure.ac
+++ b/configure.ac
@@ -20,7 +20,9 @@
 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])