diff --git a/src/Microsoft.PowerShell.Commands.Management/commands/management/Service.cs b/src/Microsoft.PowerShell.Commands.Management/commands/management/Service.cs
index 72473902466..35d0204f412 100644
--- a/src/Microsoft.PowerShell.Commands.Management/commands/management/Service.cs
+++ b/src/Microsoft.PowerShell.Commands.Management/commands/management/Service.cs
@@ -1087,17 +1087,9 @@ internal List<ServiceController> DoStopService(ServiceController serviceControll
         /// True if all dependent services are stopped
         /// False if not all dependent services are stopped
         /// </returns>
-        private bool HaveAllDependentServicesStopped(ICollection<ServiceController> dependentServices)
+        private bool HaveAllDependentServicesStopped(ServiceController[] dependentServices)
         {
-            foreach (ServiceController service in dependentServices)
-            {
-                if (service.Status != ServiceControllerStatus.Stopped)
-                {
-                    return false;
-                }
-            }
-
-            return true;
+            return Array.TrueForAll(dependentServices, service => service.Status == ServiceControllerStatus.Stopped);
         }
 
         /// <summary>
@@ -1106,14 +1098,10 @@ private bool HaveAllDependentServicesStopped(ICollection<ServiceController> depe
         /// <param name="services">A list of services.</param>
         internal void RemoveNotStoppedServices(List<ServiceController> services)
         {
-            foreach (ServiceController service in services)
-            {
-                if (service.Status != ServiceControllerStatus.Stopped &&
-                    service.Status != ServiceControllerStatus.StopPending)
-                {
-                    services.Remove(service);
-                }
-            }
+            // You shall not modify a collection during enumeration.
+            services.RemoveAll(service =>
+                service.Status != ServiceControllerStatus.Stopped &&
+                service.Status != ServiceControllerStatus.StopPending);
         }
 
         /// <summary>