diff --git a/plugins/org.jkiss.dbeaver.ext.mockdata/src/org/jkiss/dbeaver/ext/mockdata/generator/AbstractMockValueGenerator.java b/plugins/org.jkiss.dbeaver.ext.mockdata/src/org/jkiss/dbeaver/ext/mockdata/generator/AbstractMockValueGenerator.java
index 00f5d78ef32fffd01814044b3443d837b75e2e8e..222edd4687e2fa32b81d783486244741ae6feb3f 100644
--- a/plugins/org.jkiss.dbeaver.ext.mockdata/src/org/jkiss/dbeaver/ext/mockdata/generator/AbstractMockValueGenerator.java
+++ b/plugins/org.jkiss.dbeaver.ext.mockdata/src/org/jkiss/dbeaver/ext/mockdata/generator/AbstractMockValueGenerator.java
@@ -91,7 +91,7 @@ public abstract class AbstractMockValueGenerator implements MockValueGenerator {
 
             }
         }
-        if (isUnique) {
+        if (isUnique && uniqueValues != null) {
             int attempts = 0;
             Object value = null;
             while (value == null || uniqueValues.contains(value)) {