diff --git a/src/libfetchers/path.cc b/src/libfetchers/path.cc
index b35c04cfc..fb5702c4c 100644
--- a/src/libfetchers/path.cc
+++ b/src/libfetchers/path.cc
@@ -95,8 +95,11 @@ struct PathInputScheme : InputScheme
             absPath = nix::absPath(path, parent);
 
             // for security, ensure that if the parent is a store path, it's inside it
-            if (store->isInStore(parent) && !isInDir(absPath, parent))
-                throw BadStorePath("relative path '%s' [%s] points outside of its parent's store path '%s'", path, absPath, parent);
+            if (store->isInStore(parent)) {
+                auto storePath = store->printStorePath(store->toStorePath(parent).first);
+                if (!isInDir(absPath, storePath))
+                    throw BadStorePath("relative path '%s' points outside of its parent's store path '%s'", path, storePath);
+            }
         } else
             absPath = path;