diff --git a/src/fsh.nim b/src/fsh.nim
index 3787401..99ef403 100644
--- a/src/fsh.nim
+++ b/src/fsh.nim
@@ -28,6 +28,9 @@ let builtins: array[6, string] = [
 "cd",
 ]
 
+# number of frames to be used for builtins like set
+var numframes: int=1
+
 # Exception types
 type
   ShellError= object of CatchableError
@@ -254,7 +257,7 @@ proc runBuiltin(builtin: string, args: openArray[string]): (string, int) =
     of "set":
       if args.len < 2:
         raise newShellCommandException("Not enough arguments provided", "set")
-      shellVariables[0][args[0]] = args[1..^1].join(" ")
+      shellVariables[numframes-1][args[0]] = args[1..^1].join(" ")
       return ("", 0)
     of "setenv":
       if args.len < 2: