diff --git a/lib/litestream.rb b/lib/litestream.rb
index 71720ce..f43bac6 100644
--- a/lib/litestream.rb
+++ b/lib/litestream.rb
@@ -115,7 +115,7 @@ def replicate_process
           end
         end
       else
-        litestream_replicate_ps = `ps -a | grep litestream | grep replicate`.chomp
+        litestream_replicate_ps = `ps -ax | grep litestream | grep replicate`.chomp
         litestream_replicate_ps.split("\n").each do |line|
           next unless line.include?("litestream replicate")
           pid, * = line.split(" ")
diff --git a/test/test_litestream.rb b/test/test_litestream.rb
index d76e4c6..d8f0c5b 100644
--- a/test/test_litestream.rb
+++ b/test/test_litestream.rb
@@ -41,7 +41,7 @@ def test_replicate_process_ps
 
     stubbed_backticks = proc do |arg|
       case arg
-      when "ps -a | grep litestream | grep replicate"
+      when "ps -ax | grep litestream | grep replicate"
         stubbed_ps_list
       when %(ps -o "state,lstart" 40364)
         stubbed_ps_status