diff --git a/libmpdemux/ebml.c b/libmpdemux/ebml.c
index 1482cb2754..21aefb5b74 100644
--- a/libmpdemux/ebml.c
+++ b/libmpdemux/ebml.c
@@ -14,6 +14,10 @@
 #include "bswap.h"
 
 
+#ifndef SIZE_MAX
+#define SIZE_MAX ((size_t)-1)
+#endif
+
 /*
  * Read: the element content data ID.
  * Return: the ID.
diff --git a/libmpdemux/url.c b/libmpdemux/url.c
index 97cdbdb5d3..7893514ad7 100644
--- a/libmpdemux/url.c
+++ b/libmpdemux/url.c
@@ -15,6 +15,10 @@
 #include "mp_msg.h"
 #include "help_mp.h"
 
+#ifndef SIZE_MAX
+#define SIZE_MAX ((size_t)-1)
+#endif
+
 URL_t*
 url_new(const char* url) {
 	int pos1, pos2,v6addr = 0;