diff --git a/configure.ac b/configure.ac
index 66c275cd..7250e79d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -19,7 +19,7 @@ AM_CHECK_PYTHON_HEADERS(,[AC_MSG_ERROR(could not find Python headers)])
 
 AC_PATH_PROG(PYGTK_CODEGEN, pygtk-codegen-2.0, no)
 
-PKG_CHECK_MODULES(EXT, pygtk-2.0 gtk+-2.0)
+PKG_CHECK_MODULES(EXT, pygtk-2.0 gtk+-2.0, sm)
 
 PYGTK_DEFSDIR=`$PKG_CONFIG --variable=defsdir pygtk-2.0`
 AC_SUBST(PYGTK_DEFSDIR)