diff --git a/spring-batch-core/src/main/java/org/springframework/batch/core/step/tasklet/TaskletStep.java b/spring-batch-core/src/main/java/org/springframework/batch/core/step/tasklet/TaskletStep.java
index ff85108a6..354cb67ac 100644
--- a/spring-batch-core/src/main/java/org/springframework/batch/core/step/tasklet/TaskletStep.java
+++ b/spring-batch-core/src/main/java/org/springframework/batch/core/step/tasklet/TaskletStep.java
@@ -230,7 +230,8 @@ public class TaskletStep extends AbstractStep {
 				ExceptionHolder fatalException = new ExceptionHolder();
 
 				StepContribution contribution = stepExecution.createStepContribution();
-
+				stepExecution.getExecutionContext().clearDirtyFlag();
+				
 				// Before starting a new transaction, check for
 				// interruption.
 				interruptionPolicy.checkInterrupted(stepExecution);
@@ -295,6 +296,12 @@ public class TaskletStep extends AbstractStep {
 						Thread.currentThread().interrupt();
 					}
 
+					//Check to make sure the ExecutionContext hasn't be modified outside a chunk boundary.  Doing so will cause potential
+					//rollback issues.
+					if(stepExecution.getExecutionContext().isDirty()){
+						throw new IllegalStateException("The ExecutionContext cannot be modified outside of the ItemStream#Update method");
+					}
+					
 					stream.update(stepExecution.getExecutionContext());
 
 					try {
diff --git a/spring-batch-core/src/test/java/org/springframework/batch/core/step/tasklet/TaskletStepTests.java b/spring-batch-core/src/test/java/org/springframework/batch/core/step/tasklet/TaskletStepTests.java
index d86d311cd..875ae491c 100644
--- a/spring-batch-core/src/test/java/org/springframework/batch/core/step/tasklet/TaskletStepTests.java
+++ b/spring-batch-core/src/test/java/org/springframework/batch/core/step/tasklet/TaskletStepTests.java
@@ -34,6 +34,7 @@ import org.springframework.batch.core.JobExecution;
 import org.springframework.batch.core.JobInstance;
 import org.springframework.batch.core.JobInterruptedException;
 import org.springframework.batch.core.JobParameters;
+import org.springframework.batch.core.StepContribution;
 import org.springframework.batch.core.StepExecution;
 import org.springframework.batch.core.StepExecutionListener;
 import org.springframework.batch.core.job.JobSupport;
@@ -58,6 +59,7 @@ import org.springframework.batch.repeat.policy.DefaultResultCompletionPolicy;
 import org.springframework.batch.repeat.policy.SimpleCompletionPolicy;
 import org.springframework.batch.repeat.support.RepeatTemplate;
 import org.springframework.batch.support.transaction.ResourcelessTransactionManager;
+import org.springframework.core.AttributeAccessor;
 import org.springframework.dao.DataAccessResourceFailureException;
 import org.springframework.transaction.TransactionException;
 import org.springframework.transaction.support.DefaultTransactionStatus;
@@ -772,6 +774,26 @@ public class TaskletStepTests {
 		assertEquals(BatchStatus.FAILED, stepExecution.getStatus());
 
 	}
+	
+	@Test
+	 public void testModifyingExecutionContextMidProcessCausesException() throws Exception{
+		StepExecution stepExecution = new StepExecution(step.getName(), new JobExecution(jobInstance));
+		final ExecutionContext ec = stepExecution.getExecutionContext();
+		step.setTasklet(new Tasklet(){
+
+			public ExitStatus execute(StepContribution contribution,
+					AttributeAccessor attributes) throws Exception {
+
+				ec.putString("test", "test");
+				return ExitStatus.FINISHED;
+			}
+		});
+		
+		step.execute(stepExecution);
+		assertEquals(BatchStatus.FAILED, stepExecution.getStatus());
+		assertEquals(1, stepExecution.getFailureExceptions().size());
+		assertTrue(stepExecution.getFailureExceptions().get(0) instanceof IllegalStateException);
+	}
 
 	private boolean contains(String str, String searchStr) {
 		return str.indexOf(searchStr) != -1;