diff --git a/pkgs/build-support/fetchsvnssh/default.nix b/pkgs/build-support/fetchsvnssh/default.nix
index ef72de61fe21..e798044e2ea1 100644
--- a/pkgs/build-support/fetchsvnssh/default.nix
+++ b/pkgs/build-support/fetchsvnssh/default.nix
@@ -1,17 +1,19 @@
-{stdenvNoCC, subversion, sshSupport ? true, openssh ? null, expect}:
-{username, password, url, rev ? "HEAD", sha256 ? ""}:
+{lib, stdenvNoCC, subversion, sshSupport ? true, openssh ? null, expect}:
+{username, password
+, url, rev ? "HEAD"
+, outputHash ? lib.fakeHash, outputHashAlgo ? null}:
 
+lib.fetchers.withNormalizedHash { } (
+  stdenvNoCC.mkDerivation {
+    name = "svn-export-ssh";
+    builder = ./builder.sh;
+    nativeBuildInputs = [subversion expect];
 
-stdenvNoCC.mkDerivation {
-  name = "svn-export-ssh";
-  builder = ./builder.sh;
-  nativeBuildInputs = [subversion expect];
+    inherit outputHash outputHashAlgo;
+    outputHashMode = "recursive";
 
-  outputHashAlgo = "sha256";
-  outputHashMode = "recursive";
-  outputHash = sha256;
+    sshSubversion = ./sshsubversion.exp;
 
-  sshSubversion = ./sshsubversion.exp;
-
-  inherit username password url rev sshSupport openssh;
-}
+    inherit username password url rev sshSupport openssh;
+  }
+)