diff --git a/src/webp/mux.h b/src/webp/mux.h
index 26a58711..2a0fc858 100644
--- a/src/webp/mux.h
+++ b/src/webp/mux.h
@@ -22,7 +22,7 @@
 extern "C" {
 #endif
 
-#define WEBP_MUX_ABI_VERSION 0x0103        // MAJOR(8b) + MINOR(8b)
+#define WEBP_MUX_ABI_VERSION 0x0104        // MAJOR(8b) + MINOR(8b)
 
 //------------------------------------------------------------------------------
 // Mux API