diff --git a/internal/tshelpers/custom_commands.go b/internal/tshelpers/custom_commands.go
index be0bd7f40c..f2e1b3d4ea 100644
--- a/internal/tshelpers/custom_commands.go
+++ b/internal/tshelpers/custom_commands.go
@@ -397,6 +397,9 @@ func archiveFileNames(isoPath string) (string, string, error) {
 
 func expand(ts *testscript.TestScript, s []byte) string {
 	return os.Expand(string(s), func(key string) string {
+		if key == "$" {
+			return "$"
+		}
 		return ts.Getenv(key)
 	})
 }