diff --git a/lib/nmea0183ton2k/NMEA0183DataToN2K.cpp b/lib/nmea0183ton2k/NMEA0183DataToN2K.cpp
index e83731f..bc0f468 100644
--- a/lib/nmea0183ton2k/NMEA0183DataToN2K.cpp
+++ b/lib/nmea0183ton2k/NMEA0183DataToN2K.cpp
@@ -350,6 +350,10 @@ private:
             LOG_DEBUG(GwLog::DEBUG, "failed to parse RMC %s", msg.line);
             return;
         }
+        if (status != 'A' && status != 'a'){
+            LOG_DEBUG(GwLog::DEBUG, "invalid status %c for RMC %s",status, msg.line);
+            return;
+        }
         tN2kMsg n2kMsg;
         if (
             UD(GPST) &&
@@ -750,6 +754,10 @@ private:
             LOG_DEBUG(GwLog::DEBUG, "failed to parse GGA %s", msg.line);
             return;   
         }
+        if (GPSQualityIndicator == 0){
+            LOG_DEBUG(GwLog::DEBUG, "quality 0 (no fix) for GGA %s", msg.line);
+            return;   
+        }
         if (! updateDouble(boatData->GPST,GPSTime,msg.sourceId)) return;
         if (! updateDouble(boatData->LAT,Latitude,msg.sourceId)) return;        
         if (! updateDouble(boatData->LON,Longitude,msg.sourceId)) return;    
diff --git a/platformio.ini b/platformio.ini
index decf238..e5e42be 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -20,12 +20,11 @@ extra_configs=
 platform = espressif32
 framework = arduino
 lib_deps = 
-	ttlappalainen/NMEA2000-library @ ^4.17.2
-	#ttlappalainen/NMEA2000_esp32 @ ^1.0.3
-	ttlappalainen/NMEA0183 @ ^1.7.1
-	bblanchon/ArduinoJson@^6.18.5
-	ottowinter/ESPAsyncWebServer-esphome@^2.0.1
-	fastled/FastLED @ ^3.4.0
+	ttlappalainen/NMEA2000-library @ 4.17.2
+	ttlappalainen/NMEA0183 @ 1.7.1
+	bblanchon/ArduinoJson@6.18.5
+	ottowinter/ESPAsyncWebServer-esphome@2.0.1
+	fastled/FastLED @ 3.4.0
 board_build.embed_files = 
 	lib/generated/index.html.gz
 	lib/generated/index.js.gz