diff --git a/trustgraph/kg/extract_definitions/extract.py b/trustgraph/kg/extract_definitions/extract.py
index 46f18b62..334fb32d 100755
--- a/trustgraph/kg/extract_definitions/extract.py
+++ b/trustgraph/kg/extract_definitions/extract.py
@@ -87,6 +87,9 @@ class Processor(ConsumerProducer):
 
                 o = defn["definition"]
 
+                if s == "": continue
+                if o == "": continue
+
                 s_value = Value(value=str(s_uri), is_uri=True)
                 o_value = Value(value=str(o), is_uri=False)