diff --git a/Makefile.am b/Makefile.am
index eeb24f821..4eda7151b 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -178,6 +178,7 @@ dist_tmux_SOURCES = \
 	log.c \
 	menu.c \
 	mode-tree.c \
+	monitor.c \
 	names.c \
 	notify.c \
 	options-table.c \