diff --git a/rdf/include/nsRDFCID.h b/rdf/include/nsRDFCID.h
index f162198b044a..051c29eb98a5 100644
--- a/rdf/include/nsRDFCID.h
+++ b/rdf/include/nsRDFCID.h
@@ -51,4 +51,9 @@
 #define NS_RDFTREEDOCUMENT_CID \
 { 0x3d262d00, 0x8b5a, 0x11d2, { 0x8e, 0xb0, 0x0, 0x80, 0x5f, 0x29, 0xf3, 0x70 } }
 
+// {7BAF62E0-8E61-11d2-8EB1-00805F29F370}
+#define NS_RDFSTREAMDATASOURCE_CID \
+{ 0x7baf62e0, 0x8e61, 0x11d2, { 0x8e, 0xb1, 0x0, 0x80, 0x5f, 0x29, 0xf3, 0x70 } }
+
+
 #endif // nsRDFCID_h__