diff --git a/pkgs/os-specific/linux/mdadm/default.nix b/pkgs/os-specific/linux/mdadm/default.nix
index 05e0600928a3..e7aa16d3dd39 100644
--- a/pkgs/os-specific/linux/mdadm/default.nix
+++ b/pkgs/os-specific/linux/mdadm/default.nix
@@ -48,6 +48,7 @@ stdenv.mkDerivation rec {
     description = "Programs for managing RAID arrays under Linux";
     homepage = "http://neil.brown.name/blog/mdadm";
     license = licenses.gpl2;
+    mainProgram = "mdadm";
     maintainers = with maintainers; [ ekleog ];
     platforms = platforms.linux;
   };
diff --git a/pkgs/servers/tailscale/default.nix b/pkgs/servers/tailscale/default.nix
index c4f700cf40ae..05a6180fa9cd 100644
--- a/pkgs/servers/tailscale/default.nix
+++ b/pkgs/servers/tailscale/default.nix
@@ -42,6 +42,7 @@ buildGoModule {
     homepage = "https://tailscale.com";
     description = "The node agent for Tailscale, a mesh VPN built on WireGuard";
     license = licenses.bsd3;
+    mainProgram = "tailscale";
     maintainers = with maintainers; [ danderson mbaillie twitchyliquid64 jk ];
   };
 }
diff --git a/pkgs/tools/misc/tmux/default.nix b/pkgs/tools/misc/tmux/default.nix
index deb2ff2c4e12..34707ce834d4 100644
--- a/pkgs/tools/misc/tmux/default.nix
+++ b/pkgs/tools/misc/tmux/default.nix
@@ -102,6 +102,7 @@ stdenv.mkDerivation (finalAttrs: {
     changelog = "https://github.com/tmux/tmux/raw/${finalAttrs.version}/CHANGES";
     license = lib.licenses.bsd3;
     platforms = lib.platforms.unix;
+    mainProgram = "tmux";
     maintainers = with lib.maintainers; [ thammers fpletz srapenne ];
   };
 })