diff --git a/pkgs/applications/networking/browsers/moonlander/default.nix b/pkgs/applications/networking/browsers/moonlander/default.nix
index 94bbbadecc917..3aeaaf4ffa5cb 100644
--- a/pkgs/applications/networking/browsers/moonlander/default.nix
+++ b/pkgs/applications/networking/browsers/moonlander/default.nix
@@ -15,6 +15,8 @@ rustPlatform.buildRustPackage rec {
   pname = "moonlander";
   version = "unstable-2021-05-23";
 
+  cargoPatches = [ ./update-num-bigint.patch ];
+
   src = fetchFromSourcehut {
     owner = "~admicos";
     repo = "moonlander";
@@ -22,7 +24,7 @@ rustPlatform.buildRustPackage rec {
     hash = "sha256-kpaJRZPPVj8QTFfOx7nq3wN2jmyYASou7cgf+XY2RVU=";
   };
 
-  cargoHash = "sha256-DL/EtZomrZlOFjUgNm6qnrB1MpXApkYKGubi+dB8aho=";
+  cargoHash = "sha256-VXKFS9FRfTKPHuy7YhNGdF9n9BKevhM6/t2dX7JrhLg=";
 
   nativeBuildInputs = [ pkg-config ];
 
diff --git a/pkgs/applications/networking/browsers/moonlander/update-num-bigint.patch b/pkgs/applications/networking/browsers/moonlander/update-num-bigint.patch
new file mode 100644
index 0000000000000..afafe5f4aab60
--- /dev/null
+++ b/pkgs/applications/networking/browsers/moonlander/update-num-bigint.patch
@@ -0,0 +1,36 @@
+diff --git a/Cargo.lock b/Cargo.lock
+index 3353912..ab045d2 100644
+--- a/Cargo.lock
++++ b/Cargo.lock
+@@ -1,5 +1,7 @@
+ # This file is automatically @generated by Cargo.
+ # It is not intended for manual editing.
++version = 3
++
+ [[package]]
+ name = "addr2line"
+ version = "0.15.1"
+@@ -830,9 +832,9 @@ dependencies = [
+ 
+ [[package]]
+ name = "num-bigint"
+-version = "0.4.0"
++version = "0.4.4"
+ source = "registry+https://github.com/rust-lang/crates.io-index"
+-checksum = "4e0d047c1062aa51e256408c560894e5251f08925980e53cf1aa5bd00eec6512"
++checksum = "608e7659b5c3d7cba262d894801b9ec9d00de989e8a82bd4bef91d08da45cdc0"
+ dependencies = [
+  "autocfg",
+  "num-integer",
+@@ -851,9 +853,9 @@ dependencies = [
+ 
+ [[package]]
+ name = "num-traits"
+-version = "0.2.14"
++version = "0.2.17"
+ source = "registry+https://github.com/rust-lang/crates.io-index"
+-checksum = "9a64b1ec5cda2586e284722486d802acf1f7dbdc623e2bfc57e65ca1cd099290"
++checksum = "39e3200413f237f41ab11ad6d161bc7239c84dcb631773ccd7de3dfe4b5c267c"
+ dependencies = [
+  "autocfg",
+ ]