diff --git a/tools/macosx/maple_upload b/tools/macosx/maple_upload
index 3521aa1ef..7d6a66234 100755
--- a/tools/macosx/maple_upload
+++ b/tools/macosx/maple_upload
@@ -1,5 +1,7 @@
 #!/bin/bash
 
+MAXWAITCOUNT=40  # about 4000ms
+
 set -e
 
 if [ $# -lt 4 ]; then
@@ -25,13 +27,7 @@ DIR=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )
 #fi
 # ------------------  End of old code -----------------
 
-#  ----------------- IMPORTANT -----------------
-# The 2nd parameter to upload-reset is the delay after resetting before it exits
-# This value is in milliseonds
-# You may need to tune this to your system
-# 750ms to 1500ms seems to work on my Mac
-
-${DIR}/upload-reset ${dummy_port_fullpath} 750
+${DIR}/upload-reset ${dummy_port_fullpath}
 
 if [ $# -eq 5 ]; then
     dfuse_addr="--dfuse-address $5"
@@ -50,12 +46,22 @@ if [ ! -x ${DFU_UTIL} ]; then
     exit 2
 fi
 
+# wait for the DFU device after upload-reset command reboot target
+COUNTER=0
+while ! ${DFU_UTIL} -d ${usbID} -l | grep -e '^Found DFU: '  && ((COUNTER++ < ${MAXWAITCOUNT})); do
+    sleep 0.1
+done
+if ((${MAXWAITCOUNT} <= $COUNTER)); then
+    echo "$0: error: cannot find ${usbID}" >&2
+    exit 2
+fi
+
 ${DFU_UTIL} -d ${usbID} -a ${altID} -D ${binfile} -R ${dfuse_addr} -R
 
 echo -n Waiting for ${dummy_port_fullpath} serial...
 
 COUNTER=0
-while [ ! -c ${dummy_port_fullpath} ] && ((COUNTER++ < 40)); do
+while ! dd if=${dummy_port_fullpath} of=/dev/null count=0 > /dev/null 2>&1 && ((COUNTER++ < ${MAXWAITCOUNT})); do
     sleep 0.1
 done