diff --git a/tests/init.sh b/tests/init.sh
index d49d57cede..73d15fd3ad 100644
--- a/tests/init.sh
+++ b/tests/init.sh
@@ -65,7 +65,7 @@ for i in \
 done
 
 # Another ugly hack.
-sed "s|^$|PATH=$PATH|" < $NIX_DATA_DIR/nix/corepkgs/nar/nar.sh > tmp
+sed "s|^$|PATH='$PATH'|" < $NIX_DATA_DIR/nix/corepkgs/nar/nar.sh > tmp
 chmod +x tmp
 mv tmp $NIX_DATA_DIR/nix/corepkgs/nar/nar.sh