diff --git a/src/include/errno.h b/src/include/errno.h
index 03d1ebd6..d23b93ee 100644
--- a/src/include/errno.h
+++ b/src/include/errno.h
@@ -448,8 +448,8 @@ extern char missing_errfile_declaration[] __attribute__ (( deprecated ));
 /** Text file busy */
 #define ETXTBSY			( ERRFILE | PXENV_STATUS_FAILURE | 0x4d000000 )
 
-/** Operation would block */
-#define EWOULDBLOCK		( ERRFILE | PXENV_STATUS_FAILURE | 0x4e000000 )
+/** Operation would block (different from EAGAIN!) */
+#define EWOULDBLOCK		( ERRFILE | PXENV_STATUS_TFTP_OPEN | 0x4e000000 )
 
 /** Improper link */
 #define EXDEV			( ERRFILE | PXENV_STATUS_FAILURE | 0x4f000000 )