diff --git a/src/main/java/com/snowplowanalytics/snowplow/tracker/payload/TrackerPayload.java b/src/main/java/com/snowplowanalytics/snowplow/tracker/payload/TrackerPayload.java
index 61b8efa3..2cd187fe 100644
--- a/src/main/java/com/snowplowanalytics/snowplow/tracker/payload/TrackerPayload.java
+++ b/src/main/java/com/snowplowanalytics/snowplow/tracker/payload/TrackerPayload.java
@@ -44,7 +44,7 @@ public void add(final String key, final String value) {
             return;
         }
         if (value == null || value.isEmpty()) {
-            LOGGER.info("null or empty value detected: {}", value);
+            LOGGER.info("null or empty value detected: {}->{}", key, value);
             return;
         }
         LOGGER.debug("Adding new kv pair: {}->{}", key, value);