diff --git a/pkgs/applications/science/logic/vampire/default.nix b/pkgs/applications/science/logic/vampire/default.nix
index b88544544462..307c75b272bc 100644
--- a/pkgs/applications/science/logic/vampire/default.nix
+++ b/pkgs/applications/science/logic/vampire/default.nix
@@ -2,13 +2,13 @@
 
 stdenv.mkDerivation rec {
   pname = "vampire";
-  version = "4.5.1";
+  version = "4.6.1";
 
   src = fetchFromGitHub {
     owner = "vprover";
     repo = "vampire";
-    rev = version;
-    sha256 = "0q9gqyq96amdnhxgwjyv0r2sxakikp3jvmizgj2h0spfz643p8db";
+    rev = "v${version}";
+    sha256 = "0z71nxjak3ibp842r8iv37w1x3cbkrmjs88lpvxqb4sgrbyk38zd";
   };
 
   buildInputs = [ z3 zlib ];
@@ -50,7 +50,7 @@ stdenv.mkDerivation rec {
     homepage = "https://vprover.github.io/";
     description = "The Vampire Theorem Prover";
     platforms = platforms.unix;
-    license = licenses.unfree;
+    license = licenses.bsd3;
     maintainers = with maintainers; [ gebner ];
   };
 }