diff --git a/empire-db/src/main/java/org/apache/empire/db/DBCommand.java b/empire-db/src/main/java/org/apache/empire/db/DBCommand.java
index 71c6080..5d169b2 100644
--- a/empire-db/src/main/java/org/apache/empire/db/DBCommand.java
+++ b/empire-db/src/main/java/org/apache/empire/db/DBCommand.java
@@ -750,7 +750,9 @@
         DBCompareExpr where = null;
         for (int i=0; i<addlConstraints.length; i++)
         {
-            DBCompareExpr cmpExpr = addlConstraints[i]; 
+            DBCompareExpr cmpExpr = addlConstraints[i];
+            if (cmpExpr==null)
+                continue;
             // Check if prepared statements are enabled
             if (isPreparedStatementsEnabled())
             {   // use command params