diff --git a/builtin/providers/aws/resource_aws_lambda_event_source_mapping.go b/builtin/providers/aws/resource_aws_lambda_event_source_mapping.go
index 6dfb1b6f9fdd..70ca3a01c855 100644
--- a/builtin/providers/aws/resource_aws_lambda_event_source_mapping.go
+++ b/builtin/providers/aws/resource_aws_lambda_event_source_mapping.go
@@ -84,7 +84,7 @@ func resourceAwsLambdaEventSourceMappingCreate(d *schema.ResourceData, meta inte
 		EventSourceArn:   aws.String(eventSourceArn),
 		FunctionName:     aws.String(functionName),
 		StartingPosition: aws.String(d.Get("starting_position").(string)),
-		BatchSize:        aws.Int64(d.Get("batch_size").(int64)),
+		BatchSize:        aws.Int64(int64(d.Get("batch_size").(int))),
 		Enabled:          aws.Bool(d.Get("enabled").(bool)),
 	}
 
@@ -157,7 +157,7 @@ func resourceAwsLambdaEventSourceMappingUpdate(d *schema.ResourceData, meta inte
 
 	params := &lambda.UpdateEventSourceMappingInput{
 		UUID:         aws.String(d.Id()),
-		BatchSize:    aws.Int64(d.Get("batch_size").(int64)),
+		BatchSize:    aws.Int64(int64(d.Get("batch_size").(int))),
 		FunctionName: aws.String(d.Get("function_name").(string)),
 		Enabled:      aws.Bool(d.Get("enabled").(bool)),
 	}