diff --git a/netwerk/protocol/http/HttpBaseChannel.cpp b/netwerk/protocol/http/HttpBaseChannel.cpp
index dd1c8457a065..1e4070b39ef3 100644
--- a/netwerk/protocol/http/HttpBaseChannel.cpp
+++ b/netwerk/protocol/http/HttpBaseChannel.cpp
@@ -2189,7 +2189,7 @@ HttpBaseChannel::AddSecurityMessage(const nsAString &aMessageTag,
     return NS_ERROR_FAILURE;
   }
 
-  uint32_t innerWindowID = loadInfo->GetInnerWindowID();
+  auto innerWindowID = loadInfo->GetInnerWindowID();
 
   nsXPIDLString errorText;
   rv = nsContentUtils::GetLocalizedString(