diff --git a/tests/support/server.tcl b/tests/support/server.tcl
index 984270adb..b1ab38fc1 100644
--- a/tests/support/server.tcl
+++ b/tests/support/server.tcl
@@ -46,11 +46,16 @@ proc kill_server config {
     }
 
     # kill server and wait for the process to be totally exited
+    catch {exec kill $pid}
     while {[is_alive $config]} {
-        if {[incr wait 10] % 1000 == 0} {
+        incr wait 10
+
+        if {$wait >= 5000} {
+            puts "Forcing process $pid to exit..."
+            catch {exec kill -KILL $pid}
+        } elseif {$wait % 1000 == 0} {
             puts "Waiting for process $pid to exit..."
         }
-        catch {exec kill $pid}
         after 10
     }
 
diff --git a/tests/test_helper.tcl b/tests/test_helper.tcl
index 34d96606d..2ec3aad1c 100644
--- a/tests/test_helper.tcl
+++ b/tests/test_helper.tcl
@@ -345,6 +345,7 @@ proc print_help_screen {} {
         "--quiet            Don't show individual tests."
         "--single <unit>    Just execute the specified unit (see next option)."
         "--list-tests       List all the available test units."
+        "--clients <num>    Number of test clients (16)."
         "--force-failure    Force the execution of a test that always fails."
         "--help             Print this help screen."
     } "\n"]
@@ -390,6 +391,9 @@ for {set j 0} {$j < [llength $argv]} {incr j} {
         set ::client 1
         set ::test_server_port $arg
         incr j
+    } elseif {$opt eq {--clients}} {
+        set ::numclients $arg
+        incr j
     } elseif {$opt eq {--help}} {
         print_help_screen
         exit 0