diff --git a/lib/strings.nix b/lib/strings.nix
index 039a9ed1db1..5fba13822e3 100644
--- a/lib/strings.nix
+++ b/lib/strings.nix
@@ -829,7 +829,7 @@ rec {
        => false
   */
   isStorePath = x:
-    if !(isList x) && isCoercibleToString x then
+    if isSimpleCoercibleToString x then
       let str = toString x; in
       substring 0 1 str == "/"
       && dirOf str == storeDir