diff --git a/src/octoprint/util/avr_isp/stk500v2.py b/src/octoprint/util/avr_isp/stk500v2.py
index 0fe59fe0..41561c4a 100644
--- a/src/octoprint/util/avr_isp/stk500v2.py
+++ b/src/octoprint/util/avr_isp/stk500v2.py
@@ -111,8 +111,11 @@ class Stk500v2(ispBase.IspBase):
 		state = 'Start'
 		checksum = 0
 		while True:
-			s = self.serial.read()
-			if len(s) < 1:
+			for _ in range(0, 5):
+				s = self.serial.read()
+				if len(s) > 0:
+					break
+			else:
 				raise ispBase.IspError("Timeout")
 			b = struct.unpack(">B", s)[0]
 			checksum ^= b