diff --git a/modules/history-substring-search/README.md b/modules/history-substring-search/README.md
index 42919e0..3284110 100644
--- a/modules/history-substring-search/README.md
+++ b/modules/history-substring-search/README.md
@@ -63,6 +63,12 @@ _`${ZDOTDIR:-$HOME}/.zpreztorc`_:
 
 ```sh
 zstyle ':prezto:module:history-substring-search' globbing-flags ''
+
+To set the search matched against the start of each history entry, add the following line to
+_`${ZDOTDIR:-$HOME}/.zpreztorc`_:
+
+```sh
+zstyle ':prezto:module:history-substring-search' prefixed 'yes'
 ```
 
 ### Fuzzy search
diff --git a/modules/history-substring-search/init.zsh b/modules/history-substring-search/init.zsh
index d287ae4..3748325 100644
--- a/modules/history-substring-search/init.zsh
+++ b/modules/history-substring-search/init.zsh
@@ -34,6 +34,10 @@ if zstyle -t ':prezto:module:history-substring-search' case-sensitive; then
   HISTORY_SUBSTRING_SEARCH_GLOBBING_FLAGS="${HISTORY_SUBSTRING_SEARCH_GLOBBING_FLAGS//i}"
 fi
 
+if zstyle -t ':prezto:module:history-substring-search' prefixed; then
+  HISTORY_SUBSTRING_SEARCH_PREFIXED='true'
+fi
+
 if ! zstyle -t ':prezto:module:history-substring-search' color; then
   unset HISTORY_SUBSTRING_SEARCH_HIGHLIGHT_{FOUND,NOT_FOUND}
 fi