diff --git a/nix/workbench/default.nix b/nix/workbench/default.nix
index 9faf62551c4..c7fe20099ee 100644
--- a/nix/workbench/default.nix
+++ b/nix/workbench/default.nix
@@ -108,7 +108,11 @@ let
       profile = materialise-profile
         { inherit profileNix workbench;
           backendProfile =
-            backend.materialise-profile { inherit profileNix; };
+            pkgs.runCommand "workbench-profile-outputs-${profileNix.name}-${backend.name}d" {}
+              ''
+              mkdir $out
+              cp ${backend.mkBackendConf profileNix} $out/${backend.name}.conf
+              '';
         };
 
       topology = profile-topology { inherit profileNix profile; };
diff --git a/nix/workbench/docker.nix b/nix/workbench/docker.nix
index f165b4382f2..89ce9007cf1 100644
--- a/nix/workbench/docker.nix
+++ b/nix/workbench/docker.nix
@@ -22,14 +22,6 @@ let
 
       services-config = import ./profiles/services-config.nix {inherit lib workbench basePort stateDir useCabalRun enableEKG;};
 
-      materialise-profile =
-        { profileNix }:
-        pkgs.runCommand "workbench-profile-outputs-${profileNix.name}-${name}d" {}
-          ''
-          mkdir $out
-          cp ${mkBackendConf profileNix} $out/${name}.conf
-          '';
-
       ## Backend-specific Nix bits:
       ## mkBackendConf :: Profile -> SupervisorConf
       mkBackendConf =
diff --git a/nix/workbench/supervisor.nix b/nix/workbench/supervisor.nix
index cca5f02edd0..2c87633c7a3 100644
--- a/nix/workbench/supervisor.nix
+++ b/nix/workbench/supervisor.nix
@@ -22,14 +22,6 @@ let
 
       services-config = import ./profiles/services-config.nix {inherit lib workbench basePort stateDir useCabalRun enableEKG;};
 
-      materialise-profile =
-        { profileNix }:
-        pkgs.runCommand "workbench-profile-outputs-${profileNix.name}-${name}d" {}
-          ''
-          mkdir $out
-          cp ${mkBackendConf profileNix} $out/${name}.conf
-          '';
-
       ## Backend-specific Nix bits:
       ## mkBackendConf :: Profile -> SupervisorConf
       mkBackendConf =