diff --git a/src/iperf_api.c b/src/iperf_api.c
index 593f019..3c353f1 100644
--- a/src/iperf_api.c
+++ b/src/iperf_api.c
@@ -800,6 +800,8 @@ iperf_parse_arguments(struct iperf_test *test, int argc, char **argv)
     if (blksize == 0) {
 	if (test->protocol->id == Pudp)
 	    blksize = DEFAULT_UDP_BLKSIZE;
+	else if (test->protocol->id == Psctp)
+	    blksize = DEFAULT_SCTP_BLKSIZE;
 	else
 	    blksize = DEFAULT_TCP_BLKSIZE;
     }
diff --git a/src/iperf_api.h b/src/iperf_api.h
index ee63950..e04b20f 100644
--- a/src/iperf_api.h
+++ b/src/iperf_api.h
@@ -23,6 +23,7 @@ struct iperf_stream;
 #define Psctp 12
 #define DEFAULT_UDP_BLKSIZE 8192
 #define DEFAULT_TCP_BLKSIZE (128 * 1024)  /* default read/write block size */
+#define DEFAULT_SCTP_BLKSIZE (64 * 1024)
 
 /* short option equivalents, used to support options that only have long form */
 #define OPT_SCTP 1