diff --git a/pkgs/build-support/fetchsvn/nix-prefetch-svn b/pkgs/build-support/fetchsvn/nix-prefetch-svn
index e3a4cfc8acac..d15eb9a060cd 100755
--- a/pkgs/build-support/fetchsvn/nix-prefetch-svn
+++ b/pkgs/build-support/fetchsvn/nix-prefetch-svn
@@ -6,7 +6,10 @@ expHash=$3
 
 hashType=$NIX_HASH_ALGO
 if test -z "$hashType"; then
-    hashType=md5
+    hashType=sha256
+fi
+if test -z "$hashFormat"; then
+    hashFormat=--base32
 fi
 
 if test -z "$url"; then