diff --git a/lib/default.nix b/lib/default.nix
index 916f6e05190b..7e0311f6d1f1 100644
--- a/lib/default.nix
+++ b/lib/default.nix
@@ -132,6 +132,7 @@ let
       mergeAttrsWithFunc mergeAttrsConcatenateValues
       mergeAttrsNoOverride mergeAttrByFunc mergeAttrsByFuncDefaults
       mergeAttrsByFuncDefaultsClean mergeAttrBy
+      fakeSha256 fakeSha512
       nixType imap;
   });
 in lib
diff --git a/lib/deprecated.nix b/lib/deprecated.nix
index 5a3a97c476dc..15de50456612 100644
--- a/lib/deprecated.nix
+++ b/lib/deprecated.nix
@@ -270,4 +270,8 @@ rec {
      starting at zero.
   */
   imap = imap1;
+
+  # Fake hashes. Can be used as hash placeholders, when computing hash ahead isn't trivial
+  fakeSha256 = "0000000000000000000000000000000000000000000000000000000000000000";
+  fakeSha512 = "00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000";
 }