diff --git a/pkgs/development/interpreters/tcl/generic.nix b/pkgs/development/interpreters/tcl/generic.nix
index 4b9e7be129e0..535ac2bd30d0 100644
--- a/pkgs/development/interpreters/tcl/generic.nix
+++ b/pkgs/development/interpreters/tcl/generic.nix
@@ -196,6 +196,7 @@ stdenv.mkDerivation (finalAttrs: {
     homepage = "https://www.tcl.tk/";
     license = lib.licenses.tcltk;
     platforms = lib.platforms.all;
+    mainProgram = "tclsh";
     maintainers = with lib.maintainers; [ agbrooks ];
   };
 
diff --git a/pkgs/development/libraries/tk/generic.nix b/pkgs/development/libraries/tk/generic.nix
index dae3651d64be..eab95e8e5f3a 100644
--- a/pkgs/development/libraries/tk/generic.nix
+++ b/pkgs/development/libraries/tk/generic.nix
@@ -100,6 +100,7 @@ tcl.mkTclDerivation {
     homepage = "https://www.tcl.tk/";
     license = lib.licenses.tcltk;
     platforms = lib.platforms.all;
+    mainProgram = "wish";
     maintainers = [ ];
   };
 }