diff --git a/history-substring-search.zsh b/history-substring-search.zsh
index 1239529..bbeb43d 100644
--- a/history-substring-search.zsh
+++ b/history-substring-search.zsh
@@ -49,6 +49,7 @@ zmodload -F zsh/parameter
 
 HISTORY_SUBSTRING_SEARCH_HIGHLIGHT_FOUND='bg=magenta,fg=white,bold'
 HISTORY_SUBSTRING_SEARCH_HIGHLIGHT_NOT_FOUND='bg=red,fg=white,bold'
+HISTORY_SUBSTRING_SEARCH_GLOBBING_FLAGS='i' # see "Globbing Flags" in zshexpn(1)
 
 history-substring-search-begin() {
   # continue using the previous "$history_substring_search_result" by default,
@@ -66,7 +67,7 @@ history-substring-search-begin() {
     # find all occurrences of the pattern *${query}* within the history file
     # (k) turns it an array of line numbers. (on) seems to remove duplicates.
     # (on) are default options. they can be turned off by (ON).
-    history_substring_search_matches=(${(kon)history[(R)(#i)*${history_substring_search_query_escaped}*]})
+    history_substring_search_matches=(${(kon)history[(R)(#$HISTORY_SUBSTRING_SEARCH_GLOBBING_FLAGS)*${history_substring_search_query_escaped}*]})
 
     # define the range of value that $history_substring_search_match_number
     # can take: [0, $history_substring_search_number_of_matches_plus_one]
@@ -95,7 +96,7 @@ history-substring-search-highlight() {
     # among other things, the following expression yields a variable $MEND,
     # which indicates the end position of the first occurrence of
     # $history_substring_search_query_escaped in $BUFFER
-    : ${(S)BUFFER##(#mi)($history_substring_search_query##)}
+    : ${(S)BUFFER##(#m$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")