diff --git a/docs/Makefile.am b/docs/Makefile.am
index 2e5d1c8710..d21b2ad858 100644
--- a/docs/Makefile.am
+++ b/docs/Makefile.am
@@ -8,7 +8,7 @@ else
 PLUGIN_DOCS_DIRS = plugins
 endif
 
-SUBDIRS = libs $((PLUGIN_DOCS_DIRS)
+SUBDIRS = libs $(PLUGIN_DOCS_DIRS)
 DIST_SUBDIRS = libs plugins
 
 EXTRA_DIST = \