diff --git a/cnn_classification_service/cnn_classifier.py b/cnn_classification_service/cnn_classifier.py
index 617527d..fefecc3 100644
--- a/cnn_classification_service/cnn_classifier.py
+++ b/cnn_classification_service/cnn_classifier.py
@@ -12,7 +12,7 @@ import numpy
 import matplotlib.pyplot
 from tensorflow.keras.models import model_from_json
 from tensorflow.keras import optimizers
-from tensorflow.keras_preprocessing.image import ImageDataGenerator
+from keras_preprocessing.image import ImageDataGenerator
 
 
 class Classifier(object):
diff --git a/cnn_classification_service/config.py b/cnn_classification_service/config.py
index bf17a26..a0b9d6e 100644
--- a/cnn_classification_service/config.py
+++ b/cnn_classification_service/config.py
@@ -4,8 +4,8 @@ import logging
 
 
 class Config:
-    PIKA_URL = os.environ['PIKA_URL']
-    PIKA_OUTPUT_EXCHANGE = os.environ['PIKA_OUTPUT_EXCHANGE']
+    PIKA_URL = os.environ.get('PIKA_URL')
+    PIKA_OUTPUT_EXCHANGE = os.environ.get('PIKA_OUTPUT_EXCHANGE')
     PIKA_INPUT_EXCHANGE = os.environ.get('PIKA_INPUT_EXCHANGE', 'sample-ready')
 
     MODEL_INFO_URL = os.environ.get("MODEL_INFO_URL", "http://model-service/model/cnn/$default")
diff --git a/cnn_classification_service/main.py b/cnn_classification_service/main.py
index 2828a2c..b218a67 100644
--- a/cnn_classification_service/main.py
+++ b/cnn_classification_service/main.py
@@ -17,6 +17,7 @@ import sentry_sdk
 from config import Config
 
 from magic_doer import MagicDoer
+from classifier_cache import ClassifierCache
 
 
 def message_callback(channel, method, properties, body):
@@ -58,15 +59,10 @@ def message_callback(channel, method, properties, body):
 
 
 def main():
-    # setup logging
-
-    logging.basicConfig(
-        stream=sys.stdout,
-        format="%(asctime)s - %(name)s [%(levelname)s]: %(message)s",
-        level=Config.LOG_LEVEL
-    )
-
     # setup observability stuffs
+    if (not Config.PIKA_URL) or (not Config.PIKA_OUTPUT_EXCHANGE):
+        logging.error("Mandatory config parameters unset: PIKA_URL or PIKA_OUTPUT_EXCHANGE")
+        raise KeyError
 
     if Config.SENTRY_DSN:
         sentry_logging = LoggingIntegration(
@@ -112,5 +108,24 @@ def main():
     opentracing.tracer.close()
 
 
+def test_loader():
+    logging.info("Testing if model loading works...")
+    cc = ClassifierCache(Config.MODEL_INFO_URL)
+    details, classifier = cc.get_default_classifier()
+    logging.info(f"Loaded classifier: {classifier}")
+    logging.info(f"Details: {details}")
+
+
 if __name__ == '__main__':
-    main()
+    # setup logging
+
+    logging.basicConfig(
+        stream=sys.stdout,
+        format="%(asctime)s - %(name)s [%(levelname)s]: %(message)s",
+        level=Config.LOG_LEVEL
+    )
+
+    if '--test-loader' in sys.argv:
+        test_loader()
+    else:
+        main()
diff --git a/requirements.txt b/requirements.txt
index 3fa5213..b1a6947 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,7 +2,7 @@ sentry_sdk
 pika
 requests
 
-
+h5py < 3.0.0
 librosa
 keras
 numpy