diff --git a/cabal.project b/cabal.project
index 7fa33b3..0a4778d 100644
--- a/cabal.project
+++ b/cabal.project
@@ -1,3 +1,3 @@
-index-state: 2020-03-11T00:00:00Z
+index-state: 2021-03-13T00:00:00Z
 packages: free-category.cabal
 	  examples/examples.cabal
diff --git a/nix/sources.json b/nix/sources.json
index d5254c5..0424488 100644
--- a/nix/sources.json
+++ b/nix/sources.json
@@ -5,10 +5,10 @@
         "homepage": "https://input-output-hk.github.io/haskell.nix",
         "owner": "input-output-hk",
         "repo": "haskell.nix",
-        "rev": "800b536c97e58fe7e403b957941dd26ade0fe28f",
-        "sha256": "0zy6ss7qkz6997a62n0kvkdx4hqnr0ym9xn59c1isvlginn54wly",
+        "rev": "08887404bb23e7e6c49e3d4404394a6c03162c0c",
+        "sha256": "055mc75v9sa8b7xajq5vn3pqfbqnpwn6wznbisb9rpr0n8w6ds66",
         "type": "tarball",
-        "url": "https://github.com/input-output-hk/haskell.nix/archive/800b536c97e58fe7e403b957941dd26ade0fe28f.tar.gz",
+        "url": "https://github.com/input-output-hk/haskell.nix/archive/08887404bb23e7e6c49e3d4404394a6c03162c0c.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "iohk-nix": {
@@ -17,10 +17,10 @@
         "homepage": null,
         "owner": "input-output-hk",
         "repo": "iohk-nix",
-        "rev": "f2dee151a917aac96121246ed76fb17e3f9026b0",
-        "sha256": "1d8ygzczk4zbzz04j1yrwzbfld59bc6a6ar7bmlfx1j5m6fhjb8k",
+        "rev": "666e57027dca46964c6a26efcc2042b247d354a5",
+        "sha256": "0v5sgs8wf47x4csr6f70z2hi47my5r981m71nqgkj04n0sr6lz4b",
         "type": "tarball",
-        "url": "https://github.com/input-output-hk/iohk-nix/archive/f2dee151a917aac96121246ed76fb17e3f9026b0.tar.gz",
+        "url": "https://github.com/input-output-hk/iohk-nix/archive/666e57027dca46964c6a26efcc2042b247d354a5.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "niv": {
@@ -29,10 +29,10 @@
         "homepage": "https://github.com/nmattia/niv",
         "owner": "nmattia",
         "repo": "niv",
-        "rev": "9d35b9e4837ab88517210b1701127612c260eccf",
-        "sha256": "0q50xhnm8g2yfyakrh0nly4swyygxpi0a8cb9gp65wcakcgvzvdh",
+        "rev": "af958e8057f345ee1aca714c1247ef3ba1c15f5e",
+        "sha256": "1qjavxabbrsh73yck5dcq8jggvh3r2jkbr6b5nlz5d9yrqm9255n",
         "type": "tarball",
-        "url": "https://github.com/nmattia/niv/archive/9d35b9e4837ab88517210b1701127612c260eccf.tar.gz",
+        "url": "https://github.com/nmattia/niv/archive/af958e8057f345ee1aca714c1247ef3ba1c15f5e.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     }
 }