diff --git a/src/shell/scripts/omp.lua b/src/shell/scripts/omp.lua
index 0ab06c9e..570fc57e 100644
--- a/src/shell/scripts/omp.lua
+++ b/src/shell/scripts/omp.lua
@@ -46,6 +46,7 @@ end
 local function run_posh_command(command)
     command = '"'..command..'"'
     local _,ismain = coroutine.running()
+    local output
     if ismain then
         output = io.popen(command):read("*a")
     else