diff --git a/.zshrc b/.zshrc
index d9bf46b..c0549d8 100644
--- a/.zshrc
+++ b/.zshrc
@@ -62,7 +62,7 @@ setopt appendhistory autocd notify histexpiredupsfirst histsavenodups incappendh
 unsetopt beep
 bindkey -e
 
-NIX_BUILD_SHELL=zsh
+export NIX_BUILD_SHELL=zsh
 
 # vi mode
 bindkey -v