diff --git a/sys/apps/shell b/sys/apps/shell
index e02f963..3a80c7c 100644
--- a/sys/apps/shell
+++ b/sys/apps/shell
@@ -241,6 +241,9 @@ if #tArgs > 0 then
   local isUrl = not not path:match("^(https?:)//(([^/:]+):?([0-9]*))(/?.*)$")
   if not isUrl then
     path = shell.resolveProgram(path)
+    if not path then
+      error('No such program')
+    end
   end
 
   local fn, err
diff --git a/sys/etc/app.db b/sys/etc/app.db
index 1b45705..b2723c2 100644
--- a/sys/etc/app.db
+++ b/sys/etc/app.db
@@ -256,7 +256,7 @@
 \030f\031dshell]\0304\0314 \
 \0304\031f       ",
     title = "Mwm",
-    run = "wmw.lua usr/config/mwm",
+    run = "mwm.lua usr/config/mwm",
   },
   [ "8d1b0a73bedc0dc492377c2f6ab880940b97ec6e" ] = {
     icon = "\030 \031f \0305 \030    \030d \030  \
diff --git a/sys/extensions/tl3.lua b/sys/extensions/tl3.lua
index 0de9108..ce8c73f 100644
--- a/sys/extensions/tl3.lua
+++ b/sys/extensions/tl3.lua
@@ -233,9 +233,9 @@ function turtle.dropDown(count, slot) return _drop(actions.down, count, slot)
 
 function turtle.refuel(qtyOrName, qty)
   if not qtyOrName or type(qtyOrName) == 'number' then
-    return turtle.native.refuel(qtyOrName)
+    return turtle.native.refuel(qtyOrName or 64)
   end
-  return inventoryAction(turtle.native.refuel, qtyOrName, qty)
+  return inventoryAction(turtle.native.refuel, qtyOrName, qty or 64)
 end
 
 --[[