diff --git a/lib/linguist/languages.yml b/lib/linguist/languages.yml
index 88c425287f..e043f12c59 100644
--- a/lib/linguist/languages.yml
+++ b/lib/linguist/languages.yml
@@ -6953,6 +6953,7 @@ Tcl:
   - ".tcl.in"
   - ".tm"
   - ".xdc"
+  - ".exp"
   aliases:
   - sdc
   - xdc
@@ -6962,6 +6963,7 @@ Tcl:
   interpreters:
   - tclsh
   - wish
+  - expect
   tm_scope: source.tcl
   ace_mode: tcl
   codemirror_mode: tcl