diff --git a/mailnews/mime/public/nsIMimeHeaderConverter.h b/mailnews/mime/public/nsIMimeHeaderConverter.h
index 2e40701ae62c..d254c4a9941b 100644
--- a/mailnews/mime/public/nsIMimeHeaderConverter.h
+++ b/mailnews/mime/public/nsIMimeHeaderConverter.h
@@ -27,6 +27,11 @@
 #include "prtypes.h"
 #include "nsString.h"
 
+// {866A1E11-D0B9-11d2-B373-525400E2D63A}
+#define NS_MIME_HEADER_CONVERTER_CID   \
+        { 0x866a1e11, 0xd0b9, 0x11d2,         \
+        { 0xb3, 0x73, 0x52, 0x54, 0x0, 0xe2, 0xd6, 0x3a } };
+
 // {C09EDB23-B7AF-11d2-B35E-525400E2D63A}
 #define NS_IMIME_HEADER_CONVERTER_IID \
       { 0xfb953da, 0xd0b5, 0x11d2,   \
diff --git a/mailnews/mime/src/nsMimeHeaderConverter.h b/mailnews/mime/src/nsMimeHeaderConverter.h
index 54d928f9820d..d67dfb971de4 100644
--- a/mailnews/mime/src/nsMimeHeaderConverter.h
+++ b/mailnews/mime/src/nsMimeHeaderConverter.h
@@ -28,11 +28,6 @@
 #include "prtypes.h"
 #include "nsIMimeHeaderConverter.h"
 
-// {866A1E11-D0B9-11d2-B373-525400E2D63A}
-#define NS_MIME_HEADER_CONVERTER_CID   \
-        { 0x866a1e11, 0xd0b9, 0x11d2,         \
-        { 0xb3, 0x73, 0x52, 0x54, 0x0, 0xe2, 0xd6, 0x3a } };
-
 class nsMimeHeaderConverter : public nsIMimeHeaderConverter {
 public: 
   nsMimeHeaderConverter();