diff --git a/modem/api_validations.py b/modem/api_validations.py
index b8257d9c..a5cbc70e 100644
--- a/modem/api_validations.py
+++ b/modem/api_validations.py
@@ -1,5 +1,16 @@
 import re
 
+
+def validate_remote_config(config):
+    if not config:
+        return
+
+    mygrid = config["STATION"]["mygrid"]
+    if len(mygrid) != 6:
+        raise ValueError(f"Gridsquare must be 6 characters!")
+
+    return True
+
 def validate_freedata_callsign(callsign):
     #regexp = "^[a-zA-Z]+\d+\w+-\d{1,2}$"
     regexp = "^[A-Za-z0-9]{1,7}-[0-9]{1,3}$" # still broken - we need to allow all ssids form 0 - 255
diff --git a/modem/server.py b/modem/server.py
index f425b37f..8b7acd3e 100644
--- a/modem/server.py
+++ b/modem/server.py
@@ -96,6 +96,9 @@ def index():
 @app.route('/config', methods=['GET', 'POST'])
 def config():
     if request.method in ['POST']:
+
+        if not validations.validate_remote_config(request.json):
+            return api_abort("wrong config", 500)
         # check if config already exists
         if app.config_manager.read() == request.json:
             return api_response(request.json)