diff --git a/history-search-multi-word.plugin.zsh b/history-search-multi-word.plugin.zsh
index 6123236..bec42c2 100644
--- a/history-search-multi-word.plugin.zsh
+++ b/history-search-multi-word.plugin.zsh
@@ -4,6 +4,11 @@
 # to ~/.zshrc.
 #
 
+# This gives immunity to functionargzero being unset
+# _ will be set to last argument to source builtin
+PLUGIN_UNDERSCORE="$_"
+[ "$0" != "$PLUGIN_UNDERSCORE" ] && 0="$PLUGIN_UNDERSCORE"
+
 REPO_DIR="${0%/*}"
 if [[ -z "$ZPLG_CUR_PLUGIN" && "${fpath[(r)$REPO_DIR]}" != $REPO_DIR ]]; then
     fpath+=( "$REPO_DIR" )