diff --git a/mozilla/xpcom/base/nsISupportsUtils.h b/mozilla/xpcom/base/nsISupportsUtils.h
index f7190a7d492..bc4f77ac57a 100644
--- a/mozilla/xpcom/base/nsISupportsUtils.h
+++ b/mozilla/xpcom/base/nsISupportsUtils.h
@@ -557,6 +557,8 @@ NS_IMETHODIMP _class::QueryInterface(REFNSIID aIID, void** aInstancePtr)      \
 // A type-safe interface for calling |QueryInterface()|.  A similar implementation
 //	exists in "nsCOMPtr.h" for use with |nsCOMPtr|s.
 
+class nsISupports;
+
 template <class T>
 inline
 nsresult
@@ -568,4 +570,6 @@ CallQueryInterface( nsISupports* aSource, T** aDestination )
 		return aSource->QueryInterface(T::GetIID(), aDestination);
 	}
 
+////////////////////////////////////////////////////////////////////////////////
+
 #endif /* __nsISupportsUtils_h */
diff --git a/mozilla/xpcom/glue/nsISupportsUtils.h b/mozilla/xpcom/glue/nsISupportsUtils.h
index f7190a7d492..bc4f77ac57a 100644
--- a/mozilla/xpcom/glue/nsISupportsUtils.h
+++ b/mozilla/xpcom/glue/nsISupportsUtils.h
@@ -557,6 +557,8 @@ NS_IMETHODIMP _class::QueryInterface(REFNSIID aIID, void** aInstancePtr)      \
 // A type-safe interface for calling |QueryInterface()|.  A similar implementation
 //	exists in "nsCOMPtr.h" for use with |nsCOMPtr|s.
 
+class nsISupports;
+
 template <class T>
 inline
 nsresult
@@ -568,4 +570,6 @@ CallQueryInterface( nsISupports* aSource, T** aDestination )
 		return aSource->QueryInterface(T::GetIID(), aDestination);
 	}
 
+////////////////////////////////////////////////////////////////////////////////
+
 #endif /* __nsISupportsUtils_h */
diff --git a/mozilla/xpcom/public/nsISupportsUtils.h b/mozilla/xpcom/public/nsISupportsUtils.h
index f7190a7d492..bc4f77ac57a 100644
--- a/mozilla/xpcom/public/nsISupportsUtils.h
+++ b/mozilla/xpcom/public/nsISupportsUtils.h
@@ -557,6 +557,8 @@ NS_IMETHODIMP _class::QueryInterface(REFNSIID aIID, void** aInstancePtr)      \
 // A type-safe interface for calling |QueryInterface()|.  A similar implementation
 //	exists in "nsCOMPtr.h" for use with |nsCOMPtr|s.
 
+class nsISupports;
+
 template <class T>
 inline
 nsresult
@@ -568,4 +570,6 @@ CallQueryInterface( nsISupports* aSource, T** aDestination )
 		return aSource->QueryInterface(T::GetIID(), aDestination);
 	}
 
+////////////////////////////////////////////////////////////////////////////////
+
 #endif /* __nsISupportsUtils_h */