diff --git a/api/rtp_headers.h b/api/rtp_headers.h
index 13bc4f985e..44972ecb08 100644
--- a/api/rtp_headers.h
+++ b/api/rtp_headers.h
@@ -88,6 +88,8 @@ struct RTPHeaderExtension {
   absl::optional<ColorSpace> color_space;
 };
 
+enum { kRtpCsrcSize = 15 };  // RFC 3550 page 13
+
 struct RTPHeader {
   RTPHeader();
   RTPHeader(const RTPHeader& other);
diff --git a/common_types.h b/common_types.h
index d150a3d771..c156899c1a 100644
--- a/common_types.h
+++ b/common_types.h
@@ -38,9 +38,6 @@ class OverheadObserver {
   virtual void OnOverheadChanged(size_t overhead_bytes_per_packet) = 0;
 };
 
-// RTP
-enum { kRtpCsrcSize = 15 };  // RFC 3550 page 13
-
 // ==================================================================
 // Video specific types
 // ==================================================================