diff --git a/themes/agnoster.zsh-theme b/themes/agnoster.zsh-theme
index b0a794f4d..e8ecad800 100644
--- a/themes/agnoster.zsh-theme
+++ b/themes/agnoster.zsh-theme
@@ -117,7 +117,9 @@ prompt_git() {
 
     zstyle ':vcs_info:*' enable git
     zstyle ':vcs_info:*' get-revision true
-    zstyle ':vcs_info:*' check-for-changes true
+    if [[ -n $dirty ]]; then
+      zstyle ':vcs_info:*' check-for-changes true
+    fi
     zstyle ':vcs_info:*' stagedstr '✚'
     zstyle ':vcs_info:*' unstagedstr '●'
     zstyle ':vcs_info:*' formats ' %u%c'