diff --git a/hydra/fpga.json b/hydra/fpga.json
index 96769f6..fe49410 100644
--- a/hydra/fpga.json
+++ b/hydra/fpga.json
@@ -10,7 +10,7 @@
     "emailoverride": "",
     "keepnr": 10,
     "inputs": {
-        "nixpkgs": { "type": "git", "value": "git://github.com/NixOS/nixpkgs-channels nixos-unstable", "emailresponsible": false },
+        "nixpkgs": { "type": "git", "value": "git://github.com/NixOS/nixpkgs-channels nixos-19.03", "emailresponsible": false },
         "nixScripts": { "type": "git", "value": "https://git.m-labs.hk/M-Labs/nix-scripts.git", "emailresponsible": false }
     }
 }
diff --git a/hydra/fpga.nix b/hydra/fpga.nix
index cd06841..2f8ae1d 100644
--- a/hydra/fpga.nix
+++ b/hydra/fpga.nix
@@ -16,7 +16,7 @@
             "emailoverride": "",
             "keepnr": 10,
             "inputs": {
-                "nixpkgs": { "type": "git", "value": "git://github.com/NixOS/nixpkgs-channels nixos-unstable", "emailresponsible": false },
+                "nixpkgs": { "type": "git", "value": "git://github.com/NixOS/nixpkgs-channels nixos-19.03", "emailresponsible": false },
                 "heavyx": { "type": "git", "value": "https://git.m-labs.hk/M-Labs/HeavyX.git", "emailresponsible": false }
             }
         }