diff --git a/pkgs/development/interpreters/dhall/build-dhall-directory-package.nix b/pkgs/development/interpreters/dhall/build-dhall-directory-package.nix
index 7fe1b46e3a5..f7c730c9277 100644
--- a/pkgs/development/interpreters/dhall/build-dhall-directory-package.nix
+++ b/pkgs/development/interpreters/dhall/build-dhall-directory-package.nix
@@ -24,7 +24,6 @@ lib.makePackageOverridable
           code = "${src}/${file}";
 
         }
-      // lib.optionalAttrs document { documentationRoot = src; }
+      // lib.optionalAttrs document { documentationRoot = "${src}"; }
       )
   )
-