diff --git a/src/jtag3.c b/src/jtag3.c
index 9d6d5604..0c04426a 100644
--- a/src/jtag3.c
+++ b/src/jtag3.c
@@ -430,6 +430,7 @@ int jtag3_send(PROGRAMMER * pgm, unsigned char * data, size_t len)
   if (serial_send(&pgm->fd, buf, len + 4) != 0) {
     avrdude_message(MSG_INFO, "%s: jtag3_send(): failed to send command to serial port\n",
                     progname);
+    free(buf);
     return -1;
   }
 
diff --git a/src/jtagmkI.c b/src/jtagmkI.c
index fc5f3f70..2d4d83cd 100644
--- a/src/jtagmkI.c
+++ b/src/jtagmkI.c
@@ -214,6 +214,7 @@ static int jtagmkI_send(PROGRAMMER * pgm, unsigned char * data, size_t len)
   if (serial_send(&pgm->fd, buf, len + 2) != 0) {
     avrdude_message(MSG_INFO, "%s: jtagmkI_send(): failed to send command to serial port\n",
                     progname);
+    free(buf);
     return -1;
   }