diff --git a/conf.d/__async_prompt.fish b/conf.d/__async_prompt.fish
index a96103b..214869a 100644
--- a/conf.d/__async_prompt.fish
+++ b/conf.d/__async_prompt.fish
@@ -8,7 +8,7 @@ and begin
 
     function __async_prompt_setup
         set -l fish_pids (pgrep -f fish)
-        set -U -n | sed -rn 's/__async_prompt_.*_([0-9]+)/\0 \1/p' | while read -l varname pid
+        set -U -n | sed -En 's/__async_prompt_.*_([0-9]+)/\0 \1/p' | while read -l varname pid
             if not contains "$pid" fish_pids
                 set -e $varname
             end
@@ -65,7 +65,7 @@ and begin
         set st $status
 
         for func in (__async_prompt_config_functions)
-            __async_prompt_config_inherit_variables | __async_prompt_spawn $st 'set -U __async_prompt_'$func'_text_'(__async_prompt_pid)' ('$func')'
+            __async_prompt_config_inherit_variables | __async_prompt_spawn $st 'set -l prompt ('$func'); and set -U __async_prompt_'$func'_text_'(__async_prompt_pid)' $prompt'
             function '__async_prompt_'$func'_handler' --on-process-exit (jobs -lp | tail -n1)
                 kill -WINCH (__async_prompt_pid)
                 sleep 0.1
@@ -139,7 +139,13 @@ and begin
         if test -n "$pid"
             echo $pid
         else
-            cat /proc/self/stat | awk '{ print $4 }'
+            if test -n "$fish_pid"
+                # New fish pid format
+                echo $fish_pid
+            else
+                # Old fish pid format
+                echo %self
+            end
         end
     end
 end