diff --git a/src/init/omp.lua b/src/init/omp.lua
index eb80b913..c631b258 100644
--- a/src/init/omp.lua
+++ b/src/init/omp.lua
@@ -3,10 +3,21 @@
 local endedit_time
 local last_duration
 
+local function os_clock_millis()
+    -- Clink v1.2.30 has a fix for Lua's os.clock() implementation failing after
+    -- the program has been running more than 24 days.  In older versions, call
+    -- OMP to get the time in milliseconds.
+    if (clink.version_encoded or 0) >= 10020030 then
+        return math.floor(os.clock() * 1000)
+    else
+        return io.popen("::OMP:: --millis"):read("*n")
+    end
+end
+
 local function duration_onbeginedit()
     last_duration = 0
     if endedit_time then
-        local beginedit_time = io.popen("::OMP:: --millis"):read("*n")
+        local beginedit_time = os_clock_millis()
         local elapsed = beginedit_time - endedit_time
         if elapsed >= 0 then
             last_duration = elapsed
@@ -15,13 +26,27 @@ local function duration_onbeginedit()
 end
 
 local function duration_onendedit()
-    endedit_time = io.popen("::OMP:: --millis"):read("*n")
+    endedit_time = os_clock_millis()
 end
 
 -- Prompt functions
 
+local function execution_time_option()
+    if last_duration ~= nil then
+        return "--execution-time "..last_duration
+    end
+    return ""
+end
+
+local function error_level_option()
+    if os.geterrorlevel ~= nil and settings.get("cmd.get_errorlevel") then
+        return "--error "..os.geterrorlevel()
+    end
+    return ""
+end
+
 local function get_posh_prompt(rprompt)
-    local prompt_exe = string.format("::OMP:: --config=\"::CONFIG::\" --execution-time %s --error %s --rprompt=%s", last_duration, os.geterrorlevel(), rprompt)
+    local prompt_exe = string.format('::OMP:: --config="::CONFIG::" %s %s --rprompt=%s', execution_time_option(), error_level_option(), rprompt)
     prompt = io.popen(prompt_exe):read("*a")
     return prompt
 end
@@ -45,6 +70,7 @@ local function builtin_modules_onendedit()
     duration_onendedit()
 end
 
-
-clink.onbeginedit(builtin_modules_onbeginedit)
-clink.onendedit(builtin_modules_onendedit)
+if clink.onbeginedit ~= nil and clink.onendedit ~= nil then
+    clink.onbeginedit(builtin_modules_onbeginedit)
+    clink.onendedit(builtin_modules_onendedit)
+end