Remove compile warning
diff --git a/Makefile.am b/Makefile.am
index 4f96202..33406e2 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -292,7 +292,7 @@
 	$(SHELL) ./config.status --recheck
 
 # Format C API documentation
-html:
+html-local:
 # copy static file
 	for dir in $(DOCDIRSMANUAL) ; do \
 		$(MKDIR_P) $(top_builddir)/$$dir ;\