diff --git a/hibernate-envers/src/matrix/java/org/hibernate/envers/test/entities/ids/ManyToOneNotAuditedEmbId.java b/hibernate-envers/src/matrix/java/org/hibernate/envers/test/entities/ids/ManyToOneNotAuditedEmbId.java
index 91c061a52a..68e2581740 100644
--- a/hibernate-envers/src/matrix/java/org/hibernate/envers/test/entities/ids/ManyToOneNotAuditedEmbId.java
+++ b/hibernate-envers/src/matrix/java/org/hibernate/envers/test/entities/ids/ManyToOneNotAuditedEmbId.java
@@ -10,7 +10,7 @@ import org.hibernate.envers.test.entities.UnversionedStrTestEntity;
  */
 @Embeddable
 public class ManyToOneNotAuditedEmbId implements Serializable {
-    @ManyToOne
+    @ManyToOne(optional = false)
     private UnversionedStrTestEntity id;
 
     public ManyToOneNotAuditedEmbId() {
diff --git a/hibernate-envers/src/matrix/java/org/hibernate/envers/test/integration/modifiedflags/entities/PartialModifiedFlagsEntity.java b/hibernate-envers/src/matrix/java/org/hibernate/envers/test/integration/modifiedflags/entities/PartialModifiedFlagsEntity.java
index fd87732b1d..d06d16e5af 100644
--- a/hibernate-envers/src/matrix/java/org/hibernate/envers/test/integration/modifiedflags/entities/PartialModifiedFlagsEntity.java
+++ b/hibernate-envers/src/matrix/java/org/hibernate/envers/test/integration/modifiedflags/entities/PartialModifiedFlagsEntity.java
@@ -93,7 +93,8 @@ public class PartialModifiedFlagsEntity {
 
 	@Audited(withModifiedFlag = true)
     @ManyToMany
-	@CollectionTable(name = "ENTITIESMAP")
+    @CollectionTable(name = "ENTITIESMAP")
+    @MapKeyColumn(nullable = false)
     private Map<String, StrTestEntity> entitiesMap =
 			new HashMap<String, StrTestEntity>();
 
diff --git a/hibernate-envers/src/matrix/java/org/hibernate/envers/test/integration/strategy/ValidityAuditStrategyRevEndTestCustomRevEnt.java b/hibernate-envers/src/matrix/java/org/hibernate/envers/test/integration/strategy/ValidityAuditStrategyRevEndTestCustomRevEnt.java
index 46bfc5ed68..7375170d27 100644
--- a/hibernate-envers/src/matrix/java/org/hibernate/envers/test/integration/strategy/ValidityAuditStrategyRevEndTestCustomRevEnt.java
+++ b/hibernate-envers/src/matrix/java/org/hibernate/envers/test/integration/strategy/ValidityAuditStrategyRevEndTestCustomRevEnt.java
@@ -39,6 +39,7 @@ import org.junit.Test;
 import org.hibernate.Session;
 import org.hibernate.dialect.PostgreSQL82Dialect;
 import org.hibernate.dialect.SQLServerDialect;
+import org.hibernate.dialect.SybaseASE15Dialect;
 import org.hibernate.ejb.Ejb3Configuration;
 import org.hibernate.envers.strategy.ValidityAuditStrategy;
 import org.hibernate.envers.test.BaseEnversJPAFunctionalTestCase;
@@ -101,7 +102,7 @@ public class ValidityAuditStrategyRevEndTestCustomRevEnt extends BaseEnversJPAFu
 				.createSQLQuery(
 						"CREATE TABLE children_AUD(REV integer NOT NULL, REVEND integer, "
 								+ revendTimestampColumName + " "
-								+ (getDialect() instanceof SQLServerDialect ? "datetime" : "timestamp")
+								+ ((getDialect() instanceof SQLServerDialect || getDialect() instanceof SybaseASE15Dialect) ? "datetime" : "timestamp")
 								+ ", REVTYPE " + (getDialect() instanceof Oracle8iDialect ? "number(3,0)"
 								: (getDialect() instanceof PostgreSQL82Dialect ? "smallint" : "tinyint"))
 								+ ", parent_id integer, child1_id integer NULL, child2_id integer NULL)")
diff --git a/hibernate-envers/src/matrix/java/org/hibernate/envers/test/integration/strategy/ValidityAuditStrategyRevEndTsTest.java b/hibernate-envers/src/matrix/java/org/hibernate/envers/test/integration/strategy/ValidityAuditStrategyRevEndTsTest.java
index 994d9d5806..b9fc1e031a 100644
--- a/hibernate-envers/src/matrix/java/org/hibernate/envers/test/integration/strategy/ValidityAuditStrategyRevEndTsTest.java
+++ b/hibernate-envers/src/matrix/java/org/hibernate/envers/test/integration/strategy/ValidityAuditStrategyRevEndTsTest.java
@@ -40,6 +40,7 @@ import org.hibernate.Session;
 import org.hibernate.dialect.MySQL5Dialect;
 import org.hibernate.dialect.PostgreSQL82Dialect;
 import org.hibernate.dialect.SQLServerDialect;
+import org.hibernate.dialect.SybaseASE15Dialect;
 import org.hibernate.ejb.Ejb3Configuration;
 import org.hibernate.envers.enhanced.SequenceIdRevisionEntity;
 import org.hibernate.envers.strategy.ValidityAuditStrategy;
@@ -102,7 +103,7 @@ public class ValidityAuditStrategyRevEndTsTest extends BaseEnversJPAFunctionalTe
 				.createSQLQuery(
 						"CREATE TABLE children_AUD(REV integer NOT NULL, REVEND integer, "
 								+ revendTimestampColumName + " "
-								+ (getDialect() instanceof SQLServerDialect ? "datetime" : "timestamp")
+								+ ((getDialect() instanceof SQLServerDialect || getDialect() instanceof SybaseASE15Dialect ) ? "datetime" : "timestamp")
 								+ ", REVTYPE " + (getDialect() instanceof Oracle8iDialect ? "number(3,0)"
 								: (getDialect() instanceof PostgreSQL82Dialect ? "smallint" : "tinyint"))
 								+ ", parent_id integer, child1_id integer NULL, child2_id integer NULL)")
@@ -431,6 +432,11 @@ public class ValidityAuditStrategyRevEndTsTest extends BaseEnversJPAFunctionalTe
 				if (getDialect() instanceof MySQL5Dialect) {
 					// MySQL5 DATETIME column type does not contain milliseconds.
 					Assert.assertEquals(revendTimestamp.getTime(), (revEnd.getTimestamp() - (revEnd.getTimestamp() % 1000)));
+				} else if (getDialect() instanceof SybaseASE15Dialect) {
+					// Sybase "DATETIME values are accurate to 1/300 second on platforms that support this level of granularity".
+					Assert.assertEquals(
+							revendTimestamp.getTime() / 1000.0, revEnd.getTimestamp() / 1000.0, 1.0 / 300.0
+					);
 				} else {
 					Assert.assertEquals(revendTimestamp.getTime(), revEnd.getTimestamp());
 				}