diff --git a/nitrite/src/main/java/org/dizitart/no2/collection/NitriteDocument.java b/nitrite/src/main/java/org/dizitart/no2/collection/NitriteDocument.java
index 8cf2f5ec..05a36f53 100644
--- a/nitrite/src/main/java/org/dizitart/no2/collection/NitriteDocument.java
+++ b/nitrite/src/main/java/org/dizitart/no2/collection/NitriteDocument.java
@@ -308,6 +308,10 @@ private void deepPut(String[] splits, Object value) {
             throw new ValidationException("Invalid key provided");
         }
         String key = splits[0];
+        if (isNullOrEmpty(key)) {
+            throw new ValidationException("Invalid key provided");
+        }
+
         if (splits.length == 1) {
             // if last key, simply put in the current document
             put(key, value);