diff --git a/README.md b/README.md
index ac8beafab..feab82e80 100644
--- a/README.md
+++ b/README.md
@@ -32,6 +32,15 @@ custom widgets have been created (i.e., after all `zle -N` calls and after
 running `compinit`).  Widgets created later will work, but will not update the
 syntax highlighting.
 
+### Why does syntax highlighting not work while searching history?
+
+In current `zsh` versions it is not possible for `zsh-syntax-highlighting.zsh`
+to know if an incremental search is currently active and that matched parts of the
+buffer should be underlined (or otherwise highlighted). Therefore, it is not possible
+for `zsh-syntax-highlighting.zsh` to apply syntax highlighting and to underline the
+matched part of the search. While searching the history, the latter is more important,
+so syntax highlighting is disabled in this case.
+
 ### How are new releases announced?
 
 There is currently no "push" announcements channel.  However, the following
diff --git a/zsh-syntax-highlighting.zsh b/zsh-syntax-highlighting.zsh
index 634bbc24f..84508d609 100644
--- a/zsh-syntax-highlighting.zsh
+++ b/zsh-syntax-highlighting.zsh
@@ -62,6 +62,12 @@ _zsh_highlight()
   # Store the previous command return code to restore it whatever happens.
   local ret=$?
 
+  # Do not highlight in isearch (underlining done by zsh is more important in this case).
+  if [[ $WIDGET == zle-isearch-update ]] && ! (( $+ISEARCH_ACTIVE )); then
+    region_highlight=()
+    return $ret
+  fi
+
   setopt localoptions warncreateglobal
   setopt localoptions noksharrays
   local REPLY # don't leak $REPLY into global scope
@@ -313,6 +319,10 @@ _zsh_highlight_bind_widgets || {
 # E.g. remove cursor imprint, don't highlight partial paths, ...
 _zsh_highlight_set_or_wrap_special_zle_widget zle-line-finish
 
+# Always wrap special zle-isearch-update widget to be notified of updates in isearch
+_zsh_highlight_set_or_wrap_special_zle_widget zle-isearch-update
+
+
 # Resolve highlighters directory location.
 _zsh_highlight_load_highlighters "${ZSH_HIGHLIGHT_HIGHLIGHTERS_DIR:-${${0:A}:h}/highlighters}" || {
   echo 'zsh-syntax-highlighting: failed loading highlighters, exiting.' >&2