diff --git a/docs/reference/gtk/Makefile.am b/docs/reference/gtk/Makefile.am
index 47bc96dcd8..40d3d4f05b 100644
--- a/docs/reference/gtk/Makefile.am
+++ b/docs/reference/gtk/Makefile.am
@@ -106,6 +106,7 @@ CPPFLAGS += \
 	-UGTK_DISABLE_SINGLE_INCLUDES
 
 GTKDOC_LIBS = \
+	$(top_builddir)/gdk/libgdk-3.la \
 	$(top_builddir)/gtk/libgtk-3.la	\
 	$(GTK_DEP_LIBS)