diff --git a/aws/resource_aws_api_gateway2_integration.go b/aws/resource_aws_api_gateway2_integration.go
index 8912589f7881..88e17b0ec38c 100644
--- a/aws/resource_aws_api_gateway2_integration.go
+++ b/aws/resource_aws_api_gateway2_integration.go
@@ -20,6 +20,7 @@ func resourceAwsApiGateway2Integration() *schema.Resource {
 		Importer: &schema.ResourceImporter{
 			State: resourceAwsApiGateway2IntegrationImport,
 		},
+		CustomizeDiff: resourceAwsApiGateway2IntegrationCustomizeDiff,
 
 		Schema: map[string]*schema.Schema{
 			"api_id": {
@@ -279,3 +280,20 @@ func resourceAwsApiGateway2IntegrationImport(d *schema.ResourceData, meta interf
 
 	return []*schema.ResourceData{d}, nil
 }
+
+func resourceAwsApiGateway2IntegrationCustomizeDiff(diff *schema.ResourceDiff, meta interface{}) error {
+	if diff.Id() == "" {
+		// New resource.
+		integrationMethod := diff.Get("integration_method").(string)
+		integrationType := diff.Get("integration_type").(string)
+		if integrationType == apigatewayv2.IntegrationTypeMock {
+			if integrationMethod != "" {
+				return fmt.Errorf("'integration_method' must not be set when 'integration_type' is '%s'", integrationType)
+			}
+		} else if integrationMethod == "" {
+			return fmt.Errorf("'integration_method' must be set when 'integration_type' is '%s'", integrationType)
+		}
+	}
+
+	return nil
+}
diff --git a/website/docs/r/api_gateway_v2_integration.html.markdown b/website/docs/r/api_gateway_v2_integration.html.markdown
index 837833f5f86e..6a7157655cf8 100644
--- a/website/docs/r/api_gateway_v2_integration.html.markdown
+++ b/website/docs/r/api_gateway_v2_integration.html.markdown
@@ -58,7 +58,7 @@ Valid values: `AWS`, `AWS_PROXY`, `HTTP`, `HTTP_PROXY`, `MOCK`.
 * `content_handling_strategy` - (Optional) How to handle response payload content type conversions. Valid values: `CONVERT_TO_BINARY`, `CONVERT_TO_TEXT`.
 * `credentials_arn` - (Optional) The credentials required for the integration, if any.
 * `description` - (Optional) The description of the integration.
-* `integration_method` - (Optional) The integration's HTTP method.
+* `integration_method` - (Optional) The integration's HTTP method. Must be specified if `integration_type` is not `MOCK`.
 * `integration_uri` - (Optional) The URI of the Lambda function for a Lambda proxy integration, where `integration_type` is `AWS_PROXY`.
 * `passthrough_behavior` - (Optional) The pass-through behavior for incoming requests based on the Content-Type header in the request, and the available mapping templates specified as the `request_templates` attribute. Valid values: `WHEN_NO_MATCH`, `WHEN_NO_TEMPLATES`, `NEVER`. Default is `WHEN_NO_MATCH`.
 * `request_templates` - (Optional) A map of Velocity templates that are applied on the request payload based on the value of the Content-Type header sent by the client.