diff --git a/modules/cloudwatch_metrics/README.md b/modules/cloudwatch_metrics/README.md
index c30a89c..90fb0e0 100644
--- a/modules/cloudwatch_metrics/README.md
+++ b/modules/cloudwatch_metrics/README.md
@@ -65,6 +65,7 @@ No modules.
 | <a name="input_include_filters"></a> [include\_filters](#input\_include\_filters) | Namespaces to include. Mutually exclusive with exclude\_filters. | `set(string)` | `[]` | no |
 | <a name="input_kinesis_firehose"></a> [kinesis\_firehose](#input\_kinesis\_firehose) | Observe Kinesis Firehose module | <pre>object({<br>    firehose_delivery_stream = object({ arn = string })<br>    firehose_iam_policy      = object({ arn = string })<br>  })</pre> | n/a | yes |
 | <a name="input_name"></a> [name](#input\_name) | Name of Cloudwatch Metrics Stream and CloudFormation stack | `string` | `"observe-cwmetricsstream"` | no |
+| <a name="input_output_format"></a> [output\_format](#input\_output\_format) | Output format for the stream | `string` | `"json"` | no |
 | <a name="input_tags"></a> [tags](#input\_tags) | A map of tags to add to all resources | `map(string)` | `{}` | no |
 
 ## Outputs
diff --git a/modules/cloudwatch_metrics/main.tf b/modules/cloudwatch_metrics/main.tf
index 83d506d..a69b266 100644
--- a/modules/cloudwatch_metrics/main.tf
+++ b/modules/cloudwatch_metrics/main.tf
@@ -33,7 +33,7 @@ resource "aws_cloudwatch_metric_stream" "main" {
   name          = var.name
   role_arn      = local.iam_role_arn
   firehose_arn  = var.kinesis_firehose.firehose_delivery_stream.arn
-  output_format = "json"
+  output_format = var.output_format
   tags          = var.tags
 
   dynamic "include_filter" {
diff --git a/modules/cloudwatch_metrics/variables.tf b/modules/cloudwatch_metrics/variables.tf
index 7673672..bd64076 100644
--- a/modules/cloudwatch_metrics/variables.tf
+++ b/modules/cloudwatch_metrics/variables.tf
@@ -47,3 +47,10 @@ variable "tags" {
   nullable    = false
   default     = {}
 }
+
+variable "output_format" {
+  description = "Output format for the stream"
+  type        = string
+  nullable    = false
+  default     = "json"
+}