diff --git a/functions.sh b/functions.sh
index 01a51ac..e2019f6 100755
--- a/functions.sh
+++ b/functions.sh
@@ -47,7 +47,9 @@ _ps1_hook() {
 _bashrc_tmp_hook() {
     if [ ! -z "${bashrctmp:-x}" ];
     then
-        tmux set-environment bashrctmp "${bashrctmp}"
+        if [ -n "${TMUX}" ]; then
+            tmux set-environment bashrctmp "${bashrctmp}"
+        fi
     fi
 }