diff --git a/swh/loader/package/nixguix/loader.py b/swh/loader/package/nixguix/loader.py
--- a/swh/loader/package/nixguix/loader.py
+++ b/swh/loader/package/nixguix/loader.py
@@ -42,7 +42,7 @@
         self.sources = s['sources']
         self.provider_url = url
 
-        self._integrityByUrl = {s['url'][0]: s['integrity']
+        self._integrityByUrl = {s['urls'][0]: s['integrity']
                                 for s in self.sources}
 
         # The revision used to create the sources.json file. For Nix,
diff --git a/swh/loader/package/nixguix/tests/data/https_nix-community.github.io/nixpkgs-swh_sources-EOFError.json b/swh/loader/package/nixguix/tests/data/https_nix-community.github.io/nixpkgs-swh_sources-EOFError.json
--- a/swh/loader/package/nixguix/tests/data/https_nix-community.github.io/nixpkgs-swh_sources-EOFError.json
+++ b/swh/loader/package/nixguix/tests/data/https_nix-community.github.io/nixpkgs-swh_sources-EOFError.json
@@ -2,7 +2,7 @@
   "sources": [
     {
       "type": "url",
-      "url": [ "https://fail.com/truncated-archive.tgz" ],
+      "urls": [ "https://fail.com/truncated-archive.tgz" ],
       "integrity": "sha256-UB+RzIn63O0WxzqohYeWZRRzYCxyK7Kfhqi6WI0P8bE="
     }
  ],
diff --git a/swh/loader/package/nixguix/tests/data/https_nix-community.github.io/nixpkgs-swh_sources.json b/swh/loader/package/nixguix/tests/data/https_nix-community.github.io/nixpkgs-swh_sources.json
--- a/swh/loader/package/nixguix/tests/data/https_nix-community.github.io/nixpkgs-swh_sources.json
+++ b/swh/loader/package/nixguix/tests/data/https_nix-community.github.io/nixpkgs-swh_sources.json
@@ -2,12 +2,12 @@
   "sources": [
     {
       "type": "url",
-      "url": [ "https://github.com/owner-1/repository-1/revision-1.tgz" ],
+      "urls": [ "https://github.com/owner-1/repository-1/revision-1.tgz" ],
       "integrity": "sha256-3vm2Nt+O4zHf3Ovd/qsv1gKTEUwodX9FLxlrQdry0zs="
     },
     {
       "type": "url",
-      "url": [ "https://example.com/file.txt" ],
+      "urls": [ "https://example.com/file.txt" ],
       "integrity": "sha256-Q0copBCnj1b8G1iZw1k0NuYasMcx6QctleltspAgXlM="
     }
  ],
diff --git a/swh/loader/package/nixguix/tests/data/https_nix-community.github.io/nixpkgs-swh_sources.json_visit1 b/swh/loader/package/nixguix/tests/data/https_nix-community.github.io/nixpkgs-swh_sources.json_visit1
--- a/swh/loader/package/nixguix/tests/data/https_nix-community.github.io/nixpkgs-swh_sources.json_visit1
+++ b/swh/loader/package/nixguix/tests/data/https_nix-community.github.io/nixpkgs-swh_sources.json_visit1
@@ -2,17 +2,17 @@
   "sources": [
     {
       "type": "url",
-      "url": [ "https://github.com/owner-1/repository-1/revision-1.tgz" ],
+      "urls": [ "https://github.com/owner-1/repository-1/revision-1.tgz" ],
       "integrity": "sha256-3vm2Nt+O4zHf3Ovd/qsv1gKTEUwodX9FLxlrQdry0zs="
     },
     {
       "type": "url",
-      "url": [ "https://github.com/owner-2/repository-1/revision-1.tgz" ],
+      "urls": [ "https://github.com/owner-2/repository-1/revision-1.tgz" ],
       "integrity": "sha256-+vRlzTcnhMlynJGGMuAgMnUGdjpSqGabhcQ/SlRplAE="
     },
     {
       "type": "url",
-      "url": [ "https://example.com/file.txt" ],
+      "urls": [ "https://example.com/file.txt" ],
       "integrity": "sha256-Q0copBCnj1b8G1iZw1k0NuYasMcx6QctleltspAgXlM="
     }
  ],
diff --git a/swh/loader/package/nixguix/tests/test_functional.py b/swh/loader/package/nixguix/tests/test_nixguix.py
rename from swh/loader/package/nixguix/tests/test_functional.py
rename to swh/loader/package/nixguix/tests/test_nixguix.py
--- a/swh/loader/package/nixguix/tests/test_functional.py
+++ b/swh/loader/package/nixguix/tests/test_nixguix.py
@@ -70,7 +70,7 @@
     loader = NixGuixLoader(sources_url)
     loader_status = loader.load()
 
-    urls = [s['url'][0] for s in loader.sources]
+    urls = [s['urls'][0] for s in loader.sources]
     assert "https://example.com/file.txt" in urls
     assert loader_status['status'] == 'eventful'