diff --git a/docshell/base/BrowsingContext.cpp b/docshell/base/BrowsingContext.cpp
index 4a8af95b0c1..0fcb739a037 100644
--- a/docshell/base/BrowsingContext.cpp
+++ b/docshell/base/BrowsingContext.cpp
@@ -4234,7 +4234,7 @@ bool BrowsingContext::CanSet(
   return XRE_IsParentProcess() && !aSource && IsTop();
 }
 
-bool BrowsingContext::CanSet(FieldIndex<IDX_BrowserId>, const uint32_t& aValue,
+bool BrowsingContext::CanSet(FieldIndex<IDX_BrowserId>, const uint64_t& aValue,
                              ContentParent* aSource) {
   // We should only be able to set this for toplevel contexts which don't have
   // an ID yet.
diff --git a/docshell/base/BrowsingContext.h b/docshell/base/BrowsingContext.h
index e30efc99abb..7c50af51999 100644
--- a/docshell/base/BrowsingContext.h
+++ b/docshell/base/BrowsingContext.h
@@ -1485,7 +1485,7 @@ class BrowsingContext : public nsILoadContext, public nsWrapperCache {
 
   void DidSet(FieldIndex<IDX_HasSessionHistory>, bool aOldValue);
 
-  bool CanSet(FieldIndex<IDX_BrowserId>, const uint32_t& aValue,
+  bool CanSet(FieldIndex<IDX_BrowserId>, const uint64_t& aValue,
               ContentParent* aSource);
 
   bool CanSet(FieldIndex<IDX_UseErrorPages>, const bool& aUseErrorPages,