diff --git a/src/lua/core/computer.lua b/src/lua/core/computer.lua
index b11172a..b1607dc 100644
--- a/src/lua/core/computer.lua
+++ b/src/lua/core/computer.lua
@@ -113,7 +113,7 @@ function computer.signalTransformers.key_down(s, a, ascii, key, user)
     inesc = true
     return nil
   elseif inesc then
-    if ascii < 48 and ascii > 57 and ascii ~= 59 then
+    if ascii < 48 and ascii > 57 and ascii ~= 59 and ascii ~= 91 then
       inesc = false
       key = escmap[ascii] or 0
       ascii = 0
@@ -132,7 +132,7 @@ function computer.signalTransformers.key_up(s, a, ascii, key, user)
     inesc = true
     return nil
   elseif inesc then
-    if ascii < 48 and ascii > 57 and ascii ~= 59 then
+    if ascii < 48 and ascii > 57 and ascii ~= 59 and ascii ~= 91 then
       inesc = false
       key = escmap[ascii] or 0
       ascii = 0