diff --git a/src/default.nix b/src/default.nix
index 75f53ca2..e597f3fd 100644
--- a/src/default.nix
+++ b/src/default.nix
@@ -151,6 +151,7 @@ let
       dreamLock,
       fetcher ? null,
       extract ? false,
+      sourceOverrides ? oldSources: {},
     }@args:
     let
       # if dream lock is a file, read and parse it
@@ -163,6 +164,7 @@ let
           args.fetcher;
 
       fetched = fetcher rec {
+        inherit sourceOverrides;
         defaultPackage = dreamLock._generic.defaultPackage;
         defaultPackageVersion = dreamLock._generic.packages."${defaultPackage}";
         sources = dreamLock'.sources;
@@ -261,11 +263,6 @@ let
 
         dreamLockInterface = (utils.readDreamLock { inherit dreamLock; }).interface;
 
-        fetchedSources =
-          lib.recursiveUpdate
-            args.fetchedSources
-            (sourceOverrides args.fetchedSources);
-
         produceDerivation = name: pkg:
           utils.applyOverridesToPackage {
             inherit pkg;
@@ -411,7 +408,7 @@ let
           fetcher;
 
       fetchedSources = (fetchSources {
-        inherit dreamLock;
+        inherit dreamLock sourceOverrides;
         fetcher = fetcher';
       }).fetchedSources;
 
diff --git a/src/fetchers/default-fetcher.nix b/src/fetchers/default-fetcher.nix
index 227c2a83..be9f0737 100644
--- a/src/fetchers/default-fetcher.nix
+++ b/src/fetchers/default-fetcher.nix
@@ -10,6 +10,7 @@
   # sources attrset from dream lock
   defaultPackage,
   defaultPackageVersion,
+  sourceOverrides,
   sources,
   ...
 }:
@@ -31,7 +32,7 @@ let
                 source.path
               # assume path relative to main package source
               else
-                "${fetchedSources."${defaultPackage}"."${defaultPackageVersion}"}/${source.path}"
+                "${overriddenSources."${defaultPackage}"."${defaultPackageVersion}"}/${source.path}"
             else if fetchers.fetchers ? "${source.type}" then
               fetchSource {
                 source = source // {
@@ -43,8 +44,13 @@ let
           versions)
       sources;
 
+  overriddenSources =
+    lib.recursiveUpdate
+      fetchedSources
+      (sourceOverrides fetchedSources);
+
 in
 {
   # attrset: pname -> path of downloaded source
-  inherit fetchedSources;
+  fetchedSources = overriddenSources;
 }