diff --git a/dom/ipc/ProcessPriorityManager.cpp b/dom/ipc/ProcessPriorityManager.cpp
index 92d403f7959..4ee176bf461 100644
--- a/dom/ipc/ProcessPriorityManager.cpp
+++ b/dom/ipc/ProcessPriorityManager.cpp
@@ -1040,11 +1040,6 @@ ParticularProcessPriorityManager::SetPriorityNow(ProcessPriority aPriority,
                                                  ProcessCPUPriority aCPUPriority,
                                                  uint32_t aBackgroundLRU)
 {
-  if (aPriority == PROCESS_PRIORITY_UNKNOWN) {
-    MOZ_ASSERT(false);
-    return;
-  }
-
 #ifdef MOZ_NUWA_PROCESS
   // Do not attempt to change the priority of the Nuwa process
   if (mContentParent->IsNuwaProcess()) {
@@ -1052,6 +1047,11 @@ ParticularProcessPriorityManager::SetPriorityNow(ProcessPriority aPriority,
   }
 #endif
 
+  if (aPriority == PROCESS_PRIORITY_UNKNOWN) {
+    MOZ_ASSERT(false);
+    return;
+  }
+
   if (aBackgroundLRU > 0 &&
       aPriority == PROCESS_PRIORITY_BACKGROUND &&
       mPriority == PROCESS_PRIORITY_BACKGROUND) {