diff --git a/mapper_test.go b/mapper_test.go
index 3605e3d..625d55e 100644
--- a/mapper_test.go
+++ b/mapper_test.go
@@ -302,6 +302,27 @@ mappings:
 - match: test.*.*
   timer_type: wrong
   name: "foo"
+  labels: {}
+    `,
+			configBad: true,
+		},
+		// Config with good metric type.
+		{
+			config: `---
+mappings:
+- match: test.*.*
+  match_metric_type: counter
+  name: "foo"
+  labels: {}
+    `,
+		},
+		// Config with bad metric type matcher.
+		{
+			config: `---
+mappings:
+- match: test.*.*
+  match_metric_type: wrong
+  name: "foo"
   labels: {}
     `,
 			configBad: true,