diff --git a/docshell/base/nsWebShell.cpp b/docshell/base/nsWebShell.cpp
index 4f6164a0df25..aa35d6b8532f 100644
--- a/docshell/base/nsWebShell.cpp
+++ b/docshell/base/nsWebShell.cpp
@@ -2898,7 +2898,7 @@ nsWebShell:: GetLinkState(const PRUnichar* aURLSpec, nsLinkState& aState)
   char buf[256];
   char* url = buf;
 
-  if (urlStr.Length() >= sizeof(buf)) {
+  if (urlStr.Length() >= PRInt32(sizeof buf)) {
     url = new char[urlStr.Length() + 1];
   }
 
diff --git a/rdf/content/src/nsRDFContentUtils.cpp b/rdf/content/src/nsRDFContentUtils.cpp
index 2bc458e1885c..ebcda9bbb648 100644
--- a/rdf/content/src/nsRDFContentUtils.cpp
+++ b/rdf/content/src/nsRDFContentUtils.cpp
@@ -511,7 +511,7 @@ nsRDFContentUtils::MakeElementID(nsIDocument* aDocument, const nsString& aURI, n
     return NS_OK;
 }
 
-
+PRBool
 nsRDFContentUtils::IsContainedBy(nsIContent* aElement, nsIContent* aContainer)
 {
     nsCOMPtr<nsIContent> element( dont_QueryInterface(aElement) );
diff --git a/webshell/src/nsWebShell.cpp b/webshell/src/nsWebShell.cpp
index 4f6164a0df25..aa35d6b8532f 100644
--- a/webshell/src/nsWebShell.cpp
+++ b/webshell/src/nsWebShell.cpp
@@ -2898,7 +2898,7 @@ nsWebShell:: GetLinkState(const PRUnichar* aURLSpec, nsLinkState& aState)
   char buf[256];
   char* url = buf;
 
-  if (urlStr.Length() >= sizeof(buf)) {
+  if (urlStr.Length() >= PRInt32(sizeof buf)) {
     url = new char[urlStr.Length() + 1];
   }