diff --git a/dom/ipc/AppProcessChecker.cpp b/dom/ipc/AppProcessChecker.cpp
index 5b9f890ad29..a3c2b6e72b2 100644
--- a/dom/ipc/AppProcessChecker.cpp
+++ b/dom/ipc/AppProcessChecker.cpp
@@ -14,6 +14,7 @@
 #include "nsIAppsService.h"
 #include "nsIPrincipal.h"
 #include "nsIScriptSecurityManager.h"
+#include "nsPrintfCString.h"
 #include "nsIURI.h"
 #include "nsNetUtil.h"
 #include "nsServiceManagerUtils.h"
@@ -115,7 +116,11 @@ AssertAppProcess(PContentParent* aActor,
     }
   }
 
-  printf_stderr("Security problem: Content process does not have `%s'.  It will be killed.\n", aCapability);
+  NS_ERROR(
+    nsPrintfCString(
+      "Security problem: Content process does not have `%s'.  It will be killed.\n",
+      aCapability).get());
+
   static_cast<ContentParent*>(aActor)->KillHard();
 
   return false;
@@ -133,7 +138,11 @@ AssertAppStatus(PContentParent* aActor,
     }
   }
 
-  printf_stderr("Security problem: Content process does not have `%d' status.  It will be killed.\n", aStatus);
+  NS_ERROR(
+    nsPrintfCString(
+      "Security problem: Content process does not have `%d' status.  It will be killed.",
+      aStatus).get());
+
   static_cast<ContentParent*>(aActor)->KillHard();
 
   return false;
diff --git a/dom/ipc/ContentParent.cpp b/dom/ipc/ContentParent.cpp
index 4ae5486dd9f..eea759a8f3a 100644
--- a/dom/ipc/ContentParent.cpp
+++ b/dom/ipc/ContentParent.cpp
@@ -1984,8 +1984,11 @@ ContentParent::RecvNuwaReady()
 {
 #ifdef MOZ_NUWA_PROCESS
     if (!IsNuwaProcess()) {
-        printf_stderr("Terminating child process %d for unauthorized IPC message: "
-                      "NuwaReady", Pid());
+        NS_ERROR(
+            nsPrintfCString(
+                "Terminating child process %d for unauthorized IPC message: NuwaReady",
+                Pid()).get());
+
         KillHard();
         return false;
     }
@@ -2003,8 +2006,11 @@ ContentParent::RecvAddNewProcess(const uint32_t& aPid,
 {
 #ifdef MOZ_NUWA_PROCESS
     if (!IsNuwaProcess()) {
-        printf_stderr("Terminating child process %d for unauthorized IPC message: "
-                      "AddNewProcess(%d)", Pid(), aPid);
+        NS_ERROR(
+            nsPrintfCString(
+                "Terminating child process %d for unauthorized IPC message: "
+                "AddNewProcess(%d)", Pid(), aPid).get());
+
         KillHard();
         return false;
     }