diff --git a/taar/recommenders/lazys3.py b/taar/recommenders/lazys3.py
index 69fb356..aec01f5 100644
--- a/taar/recommenders/lazys3.py
+++ b/taar/recommenders/lazys3.py
@@ -10,7 +10,7 @@ import time
 class LazyJSONLoader:
     def __init__(self, ctx, s3_bucket, s3_key, ttl=14400):
         self._ctx = ctx
-        self.logger = self._ctx[IMozLogging].get_logger('taar')
+        self.logger = self._ctx[IMozLogging].get_logger("taar")
         self._clock = self._ctx[IClock]
 
         self._s3_bucket = s3_bucket
@@ -21,13 +21,22 @@ class LazyJSONLoader:
         self._key_str = "{}|{}".format(self._s3_bucket, self._s3_key)
 
         self._cached_copy = None
-        msg = "Cache expiry of {} is set to TTL of {} seconds".format(self._key_str, self._ttl)
+        msg = "Cache expiry of {} is set to TTL of {} seconds".format(
+            self._key_str, self._ttl
+        )
         self.logger.info(msg)
 
         self._lock = threading.RLock()
 
         self.logger.info("{} loader is initialized".format(self._key_str))
 
+    def force_expiry(self):
+        msg = "Existing model for {} reset to 0. Model was:".format(
+            self._key_str, str(self._cached_copy)
+        )
+        self.logger.info(msg)
+        self._expiry_time = 0
+
     def has_expired(self):
         return self._clock.time() > self._expiry_time
 
@@ -63,26 +72,22 @@ class LazyJSONLoader:
             raw_bytes = None
             try:
                 # We need to force a data reload from S3
-                config = Config(connect_timeout=10, retries={'max_attempts': 3})
-                s3 = boto3.resource('s3', config=config)
+                config = Config(connect_timeout=10, retries={"max_attempts": 3})
+                s3 = boto3.resource("s3", config=config)
 
                 start_load = time.time()
                 raw_bytes = (
-                    s3
-                    .Object(self._s3_bucket, self._s3_key)
-                    .get()['Body']
-                    .read()
+                    s3.Object(self._s3_bucket, self._s3_key).get()["Body"].read()
                 )
                 end_load = time.time()
-                load_time = (end_load - start_load)
-                msg = "Loaded JSON from S3: {}. Byte count: {:d}.  Time to Load: {:0.3f}"
+                load_time = end_load - start_load
+
+                raw_data = raw_bytes.decode("utf-8")
+
+                msg = "Loaded S3: {}. Byte count: {:d}.  Time to Load: {:0.3f}"
                 msg_params = self._key_str, len(raw_bytes), load_time
                 self.logger.info(msg.format(*msg_params))
 
-                raw_data = (
-                    raw_bytes.decode('utf-8')
-                )
-
                 # It is possible to have corrupted files in S3, so
                 # protect against that.
                 try:
@@ -97,9 +102,10 @@ class LazyJSONLoader:
                     # requests.
                     self._expiry_time = 0
 
-                    self.logger.error("Cannot parse JSON resource from S3", extra={
-                        "bucket": self._s3_bucket,
-                        "key": self._s3_key})
+                    self.logger.error(
+                        "Cannot parse JSON resource from S3",
+                        extra={"bucket": self._s3_bucket, "key": self._s3_key},
+                    )
 
                 return self._cached_copy
             except Exception:
@@ -109,7 +115,8 @@ class LazyJSONLoader:
                 # requests.
                 self._expiry_time = 0
 
-                self.logger.exception("Failed to download from S3", extra={
-                    "bucket": self._s3_bucket,
-                    "key": self._s3_key})
+                self.logger.exception(
+                    "Failed to download from S3",
+                    extra={"bucket": self._s3_bucket, "key": self._s3_key},
+                )
                 return self._cached_copy
diff --git a/tests/test_lazys3.py b/tests/test_lazys3.py
new file mode 100644
index 0000000..2a9d8af
--- /dev/null
+++ b/tests/test_lazys3.py
@@ -0,0 +1,94 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this file,
+# You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import json
+
+from taar.recommenders.lazys3 import LazyJSONLoader
+
+import boto3
+from moto import mock_s3
+
+
+from taar.recommenders.s3config import (
+    TAAR_SIMILARITY_BUCKET,
+    TAAR_SIMILARITY_DONOR_KEY,
+)
+
+
+def install_categorical_data(ctx):
+    ctx = ctx.child()
+    conn = boto3.resource("s3", region_name="us-west-2")
+
+    try:
+        conn.create_bucket(Bucket=TAAR_SIMILARITY_BUCKET)
+    except Exception:
+        pass
+
+    conn.Object(TAAR_SIMILARITY_BUCKET, TAAR_SIMILARITY_DONOR_KEY).put(
+        Body=json.dumps({"test": "donor_key"})
+    )
+
+    ctx["similarity_donors_pool"] = LazyJSONLoader(
+        ctx, TAAR_SIMILARITY_BUCKET, TAAR_SIMILARITY_DONOR_KEY
+    )
+
+    return ctx
+
+
+@mock_s3
+def test_does_it_load(test_ctx):
+    ctx = install_categorical_data(test_ctx)
+
+    jdata, status = ctx["similarity_donors_pool"].get()
+    assert jdata["test"] == "donor_key"
+    check_jdata_status(jdata, status)
+
+
+@mock_s3
+def test_cached_load(test_ctx):
+    ctx = install_categorical_data(test_ctx)
+    loader = ctx["similarity_donors_pool"]
+    jdata, status = loader.get()
+    check_jdata_status(jdata, status)
+    jdata, status = loader.get()
+    assert not status
+
+
+@mock_s3
+def test_reload_on_expiry(test_ctx):
+    ctx = install_categorical_data(test_ctx)
+    loader = ctx["similarity_donors_pool"]
+
+    jdata, status = loader.get()
+    check_jdata_status(jdata, status)
+    jdata, status = loader.get()
+    assert not status
+
+    # Force expirty time to be 10 seconds ago
+    loader._expiry_time = loader._clock.time() - 10
+
+    jdata, status = loader.get()
+    check_jdata_status(jdata, status)
+
+
+@mock_s3
+def test_force_expiry(test_ctx):
+    ctx = install_categorical_data(test_ctx)
+    loader = ctx["similarity_donors_pool"]
+
+    jdata, status = loader.get()
+    check_jdata_status(jdata, status)
+    jdata, status = loader.get()
+    assert not status
+
+    # Force expirty time to be 10 seconds ago
+    loader.force_expiry()
+
+    jdata, status = loader.get()
+    check_jdata_status(jdata, status)
+
+
+def check_jdata_status(jdata, status):
+    assert jdata == {'test': 'donor_key'}
+    assert status