diff --git a/tests/unit/obuf-limits.tcl b/tests/unit/obuf-limits.tcl
index 456d3ac82..38a643385 100644
--- a/tests/unit/obuf-limits.tcl
+++ b/tests/unit/obuf-limits.tcl
@@ -31,7 +31,11 @@ start_server {tags {"obuf-limits"}} {
         set start_time 0
         set time_elapsed 0
         while 1 {
-            r publish foo bar
+            if {$start_time != 0} {
+                # Slow down loop when omen has reached the limit.
+                after 10
+            }
+            r publish foo [string repeat "x" 1000]
             set clients [split [r client list] "\r\n"]
             set c [split [lindex $clients 1] " "]
             if {![regexp {omem=([0-9]+)} $c - omem]} break
@@ -57,7 +61,11 @@ start_server {tags {"obuf-limits"}} {
         set start_time 0
         set time_elapsed 0
         while 1 {
-            r publish foo bar
+            if {$start_time != 0} {
+                # Slow down loop when omen has reached the limit.
+                after 10
+            }
+            r publish foo [string repeat "x" 1000]
             set clients [split [r client list] "\r\n"]
             set c [split [lindex $clients 1] " "]
             if {![regexp {omem=([0-9]+)} $c - omem]} break