diff --git a/includes/decoders/zvei.py b/includes/decoders/zvei.py
index 94d5912..efbf661 100644
--- a/includes/decoders/zvei.py
+++ b/includes/decoders/zvei.py
@@ -13,7 +13,8 @@ def decode(freq, decoded):
 	timestamp = int(time.time())#Get Timestamp                  
 
 	zvei_id = decoded[7:12] #ZVEI Code  
-	if re.search("[0-9F]{5}", zvei_id): #if ZVEI is valid
+	zvei_id = resolveWDHtone(zvei_id) #resolve F
+	if re.search("[0-9]{5}", zvei_id): #if ZVEI is valid
 		if zvei_id == globals.zvei_id_old and timestamp < globals.zvei_time_old + globals.config.getint("ZVEI", "double_ignore_time"): #check for double alarm
 			logging.info("ZVEI double alarm: %s within %s second(s)", globals.zvei_id_old, timestamp-globals.zvei_time_old)
 			globals.zvei_time_old = timestamp #in case of double alarm, zvei_double_ignore_time set new
@@ -26,4 +27,13 @@ def decode(freq, decoded):
 			globals.zvei_id_old = zvei_id #save last id
 			globals.zvei_time_old = timestamp #save last time
 	else:
-		logging.warning("No valid ZVEI: %s", zvei_id)
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+		logging.warning("No valid ZVEI: %s", zvei_id)
+	
+
+def resolveWDHtone(zvei):
+	zvei_old = zvei
+	for i in range(1, 5):
+		if zvei[i] == "F":
+			zvei = zvei.replace("F",zvei[i-1],1)
+	logging.debug("resolve F: %s -> %s", zvei_old, zvei)
+	return zvei
\ No newline at end of file