diff --git a/src/main/java/org/springframework/samples/petclinic/repository/jdbc/JdbcPetRepositoryImpl.java b/src/main/java/org/springframework/samples/petclinic/repository/jdbc/JdbcPetRepositoryImpl.java
index 77bb221..b010e45 100644
--- a/src/main/java/org/springframework/samples/petclinic/repository/jdbc/JdbcPetRepositoryImpl.java
+++ b/src/main/java/org/springframework/samples/petclinic/repository/jdbc/JdbcPetRepositoryImpl.java
@@ -21,6 +21,7 @@
 
 import javax.sql.DataSource;
 
+import org.joda.time.LocalDate;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.dao.DataAccessException;
 import org.springframework.dao.EmptyResultDataAccessException;
@@ -124,12 +125,16 @@ public void save(Pet pet) throws DataAccessException {
      * Creates a {@link MapSqlParameterSource} based on data values from the supplied {@link Pet} instance.
      */
     private MapSqlParameterSource createPetParameterSource(Pet pet) {
+        LocalDate birthDate = pet.getBirthDate();
+        PetType type = pet.getType();
+        Owner owner = pet.getOwner();
+
         return new MapSqlParameterSource()
             .addValue("id", pet.getId())
             .addValue("name", pet.getName())
-            .addValue("birth_date", pet.getBirthDate().toDate())
-            .addValue("type_id", pet.getType().getId())
-            .addValue("owner_id", pet.getOwner().getId());
+            .addValue("birth_date", birthDate == null ? null : birthDate.toDate())
+            .addValue("type_id", type == null ? null : type.getId())
+            .addValue("owner_id", owner == null ? null : owner.getId());
     }
 
 }
diff --git a/src/main/java/org/springframework/samples/petclinic/repository/jdbc/JdbcVisitRepositoryImpl.java b/src/main/java/org/springframework/samples/petclinic/repository/jdbc/JdbcVisitRepositoryImpl.java
index 330ca1a..49accd8 100644
--- a/src/main/java/org/springframework/samples/petclinic/repository/jdbc/JdbcVisitRepositoryImpl.java
+++ b/src/main/java/org/springframework/samples/petclinic/repository/jdbc/JdbcVisitRepositoryImpl.java
@@ -15,11 +15,13 @@
  */
 package org.springframework.samples.petclinic.repository.jdbc;
 
+import org.joda.time.DateTime;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.dao.DataAccessException;
 import org.springframework.jdbc.core.JdbcTemplate;
 import org.springframework.jdbc.core.namedparam.MapSqlParameterSource;
 import org.springframework.jdbc.core.simple.SimpleJdbcInsert;
+import org.springframework.samples.petclinic.model.Pet;
 import org.springframework.samples.petclinic.model.Visit;
 import org.springframework.samples.petclinic.repository.VisitRepository;
 import org.springframework.stereotype.Repository;
@@ -71,11 +73,14 @@ public void save(Visit visit) throws DataAccessException {
      * Creates a {@link MapSqlParameterSource} based on data values from the supplied {@link Visit} instance.
      */
     private MapSqlParameterSource createVisitParameterSource(Visit visit) {
+        DateTime date = visit.getDate();
+        Pet pet = visit.getPet();
+
         return new MapSqlParameterSource()
             .addValue("id", visit.getId())
-            .addValue("visit_date", visit.getDate().toDate())
+            .addValue("visit_date", date == null ? null : date.toDate())
             .addValue("description", visit.getDescription())
-            .addValue("pet_id", visit.getPet().getId());
+            .addValue("pet_id", pet == null ? null : pet.getId());
     }
 
     @Override