Enable silent automake rules.
diff --git a/configure.ac b/configure.ac
index bc76603..e953199 100644
--- a/configure.ac
+++ b/configure.ac
@@ -34,6 +34,9 @@
 AC_SYS_LARGEFILE
 AC_FUNC_ALLOCA
 
+# Enable quiet compiles on automake 1.11.
+m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
+
 PKG_CHECK_MODULES(PTHREADSTUBS, pthread-stubs)
 AC_SUBST(PTHREADSTUBS_CFLAGS)
 AC_SUBST(PTHREADSTUBS_LIBS)