diff --git a/pom.xml b/pom.xml
index 18185ec..a5fe826 100644
--- a/pom.xml
+++ b/pom.xml
@@ -5,7 +5,7 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>net.helenus</groupId>
     <artifactId>helenus-core</artifactId>
-    <version>2.0.38-SNAPSHOT</version>
+    <version>2.0.39-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>helenus</name>
diff --git a/src/main/java/net/helenus/core/operation/SelectOperation.java b/src/main/java/net/helenus/core/operation/SelectOperation.java
index 358eb2f..c5d2fdc 100644
--- a/src/main/java/net/helenus/core/operation/SelectOperation.java
+++ b/src/main/java/net/helenus/core/operation/SelectOperation.java
@@ -193,7 +193,7 @@ public final class SelectOperation<E> extends AbstractFilterStreamOperation<E, S
           if (filter != null) {
             keys.add(filter.toString());
           } else {
-            keys.add(prop.getColumnName() + "==?");
+            return null;
           }
           break;
         default: