diff --git a/pkgs/development/libraries/libcbor/default.nix b/pkgs/development/libraries/libcbor/default.nix
index 105b1f43aec1..4d56c0f1403b 100644
--- a/pkgs/development/libraries/libcbor/default.nix
+++ b/pkgs/development/libraries/libcbor/default.nix
@@ -2,7 +2,7 @@
 
 stdenv.mkDerivation rec {
   pname = "libcbor";
-  version = "2019-07-25";
+  version = "unstable-2019-07-25";
 
   src = fetchFromGitHub {
     owner = "PJK";