diff --git a/history-substring-search.zsh b/history-substring-search.zsh
index b5b5706..d4f6a54 100644
--- a/history-substring-search.zsh
+++ b/history-substring-search.zsh
@@ -205,9 +205,9 @@ history-substring-search-highlight() {
     # which indicates the end position of the first occurrence of
     # $history_substring_search_query_escaped in $BUFFER
     : ${(S)BUFFER##(#m$HISTORY_SUBSTRING_SEARCH_GLOBBING_FLAGS)($history_substring_search_query##)}
-    let "history_substring_search_query_mbegin = $MEND - $#history_substring_search_query"
-    # this is slightly more informative than highlighting that fish performs
-    region_highlight+=("$history_substring_search_query_mbegin $MEND $1")
+    let "history_substring_search_query_mbegin = $MBEGIN - 1"
+    let "history_substring_search_query_mend = $history_substring_search_query_mbegin + $#history_substring_search_query"
+    region_highlight+=("$history_substring_search_query_mbegin $history_substring_search_query_mend $1")
   fi
 }