diff --git a/third_party/libmkv/WebMElement.h b/third_party/libmkv/WebMElement.h
index d9ad0a0..717e739 100644
--- a/third_party/libmkv/WebMElement.h
+++ b/third_party/libmkv/WebMElement.h
@@ -10,11 +10,6 @@
#ifndef MKV_CONTEXT_HPP
#define MKV_CONTEXT_HPP 1
-void writeSimpleBock(EbmlGlobal *ebml, unsigned char trackNumber, unsigned short timeCode,
- int isKeyframe, unsigned char lacingFlag, int discardable,
- unsigned char *data, unsigned long dataLength);
-
-
// these are helper functions
void writeHeader(EbmlGlobal *ebml);
void writeSegmentInformation(EbmlGlobal *ebml, EbmlLoc *startInfo, unsigned long timeCodeScale, double duration);