diff --git a/pkgs/development/interpreters/erlang/R18.nix b/pkgs/development/interpreters/erlang/R18.nix
index 0d20ae662a50..39a1a8a0048e 100644
--- a/pkgs/development/interpreters/erlang/R18.nix
+++ b/pkgs/development/interpreters/erlang/R18.nix
@@ -1,14 +1,14 @@
-{ mkDerivation, fetchurl }:
+{ mkDerivation, fetchpatch }:
 
 let
-  rmAndPwdPatch = fetchurl {
+  rmAndPwdPatch = fetchpatch {
      url = "https://github.com/erlang/otp/commit/98b8650d22e94a5ff839170833f691294f6276d0.patch";
-     sha256 = "0cd5pkqrigiqz6cyma5irqwzn0bi17k371k9vlg8ir31h3zmqfip";
+     sha256 = "0zjs7as83prgq4d5gaw2cmnajnsprdk8cjl5kklknx0pc2b3hfg5";
   };
 
-  envAndCpPatch = fetchurl {
+  envAndCpPatch = fetchpatch {
      url = "https://github.com/erlang/otp/commit/9f9841eb7327c9fe73e84e197fd2965a97b639cf.patch";
-     sha256 = "10h5348p6g279b4q01i5jdqlljww5chcvrx5b4b0dv79pk0p0m9f";
+     sha256 = "00fx5wc88ki3z71z5q4xzi9h3whhjw1zblpn09w995ygn07m9qhm";
   };
 
 in mkDerivation rec {