diff --git a/configure.ac b/configure.ac
index 2fbaf76b..1c117ce7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -29,6 +29,9 @@ PKG_CHECK_MODULES(LIB, gtk+-2.0 xulrunner-gtkmozembed)
 MOZILLA_HOME="`$PKG_CONFIG --variable=libdir xulrunner-gtkmozembed`"
 AC_SUBST(MOZILLA_HOME)
 
+MOZILLA_INCLUDE_DIR="`$PKG_CONFIG --variable=includedir xulrunner-gtkmozembed`"
+AC_SUBST(MOZILLA_INCLUDE_DIR)
+
 GNOMEPYTHONEXTRAS_DEFSDIR=`$PKG_CONFIG --variable=defsdir pygtk-2.0`
 AC_SUBST(GNOMEPYTHONEXTRAS_DEFSDIR)
 
diff --git a/lib/src/Makefile.am b/lib/src/Makefile.am
index 03c3f76b..9dc7455e 100644
--- a/lib/src/Makefile.am
+++ b/lib/src/Makefile.am
@@ -1,6 +1,7 @@
-INCLUDES =			\
-	$(WARN_CFLAGS)		\
-	$(LIB_CFLAGS)
+INCLUDES =					\
+	$(WARN_CFLAGS)				\
+	$(LIB_CFLAGS)				\
+	-I$(MOZILLA_INCLUDE_DIR)/exthandler
 
 noinst_LTLIBRARIES = libsugarprivate.la