diff --git a/base.sh b/base.sh
index f031126..14d6930 100644
--- a/base.sh
+++ b/base.sh
@@ -26,7 +26,7 @@ function build_prompt {
             just_init=true
         else
             upstream=$(git rev-parse --symbolic-full-name --abbrev-ref @{upstream} 2> /dev/null)
-            if [[ -n $upstream ]]; then has_upstream=true; else has_upstream=false; fi
+            if [ -n $upstream -a "$upstream" != "@upstream}" ]; then has_upstream=true; else has_upstream=false; fi
         
             git_status=$(git status --porcelain 2> /dev/null)