diff --git a/azurerm/resource_arm_metric_alertrule.go b/azurerm/resource_arm_metric_alertrule.go
index 82018f065ad3..a8d0150fa6c8 100644
--- a/azurerm/resource_arm_metric_alertrule.go
+++ b/azurerm/resource_arm_metric_alertrule.go
@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"log"
 
+	"strings"
+
 	"github.com/Azure/azure-sdk-for-go/services/monitor/mgmt/2017-05-01-preview/insights"
 	"github.com/hashicorp/terraform/helper/schema"
 	"github.com/hashicorp/terraform/helper/validation"
@@ -138,7 +140,12 @@ func resourceArmMetricAlertRule() *schema.Resource {
 				},
 			},
 
-			"tags": tagsForMetricAlertRuleSchema(),
+			"tags": {
+				Type:         schema.TypeMap,
+				Optional:     true,
+				Computed:     true,
+				ValidateFunc: validateMetricAlertRuleTags,
+			},
 		},
 	}
 }
@@ -414,3 +421,18 @@ func resourceGroupAndAlertRuleNameFromId(alertRuleId string) (string, string, er
 
 	return resourceGroup, name, nil
 }
+
+func validateMetricAlertRuleTags(v interface{}, f string) (ws []string, es []error) {
+	// Normal validation required by any AzureRM resource.
+	ws, es = validateAzureRMTags(v, f)
+
+	tagsMap := v.(map[string]interface{})
+
+	for k := range tagsMap {
+		if strings.EqualFold(k, "$type") {
+			es = append(es, fmt.Errorf("the %q is not allowed as tag name", k))
+		}
+	}
+
+	return ws, es
+}
diff --git a/azurerm/resource_arm_metric_alertrule_test.go b/azurerm/resource_arm_metric_alertrule_test.go
index 0df638ff0d8c..c4e0a2254b21 100644
--- a/azurerm/resource_arm_metric_alertrule_test.go
+++ b/azurerm/resource_arm_metric_alertrule_test.go
@@ -11,6 +11,60 @@ import (
 	"github.com/terraform-providers/terraform-provider-azurerm/azurerm/utils"
 )
 
+func TestValidateMetricAlertRuleTags(t *testing.T) {
+	cases := []struct {
+		Name     string
+		Value    map[string]interface{}
+		ErrCount int
+	}{
+		{
+			Name: "Single Valid",
+			Value: map[string]interface{}{
+				"hello": "world",
+			},
+			ErrCount: 0,
+		},
+		{
+			Name: "Single Invalid",
+			Value: map[string]interface{}{
+				"$Type": "hello/world",
+			},
+			ErrCount: 1,
+		},
+		{
+			Name: "Single Invalid lowercase",
+			Value: map[string]interface{}{
+				"$type": "hello/world",
+			},
+			ErrCount: 1,
+		},
+		{
+			Name: "Multiple Valid",
+			Value: map[string]interface{}{
+				"hello": "world",
+				"foo":   "bar",
+			},
+			ErrCount: 0,
+		},
+		{
+			Name: "Multiple Invalid",
+			Value: map[string]interface{}{
+				"hello": "world",
+				"$type": "Microsoft.Foo/Bar",
+			},
+			ErrCount: 1,
+		},
+	}
+
+	for _, tc := range cases {
+		_, errors := validateMetricAlertRuleTags(tc.Value, "azurerm_metric_alert_rule")
+
+		if len(errors) != tc.ErrCount {
+			t.Fatalf("Expected %q to return %d errors but returned %d", tc.Name, tc.ErrCount, len(errors))
+		}
+	}
+}
+
 func TestAccAzureRMMetricAlertRule_virtualMachineCpu(t *testing.T) {
 	resourceName := "azurerm_metric_alertrule.test"
 	ri := acctest.RandInt()
diff --git a/azurerm/tags.go b/azurerm/tags.go
index 689fa74074d5..cbb70069b84d 100644
--- a/azurerm/tags.go
+++ b/azurerm/tags.go
@@ -34,15 +34,6 @@ func tagsForDataSourceSchema() *schema.Schema {
 	}
 }
 
-func tagsForMetricAlertRuleSchema() *schema.Schema {
-	return &schema.Schema{
-		Type:         schema.TypeMap,
-		Optional:     true,
-		Computed:     true,
-		ValidateFunc: validateMetricAlertRuleTags,
-	}
-}
-
 func tagValueToString(v interface{}) (string, error) {
 	switch value := v.(type) {
 	case string:
@@ -77,21 +68,6 @@ func validateAzureRMTags(v interface{}, f string) (ws []string, es []error) {
 	return ws, es
 }
 
-func validateMetricAlertRuleTags(v interface{}, f string) (ws []string, es []error) {
-	// Normal validation required by any AzureRM resource.
-	ws, es = validateAzureRMTags(v, f)
-
-	tagsMap := v.(map[string]interface{})
-
-	for k := range tagsMap {
-		if strings.EqualFold(k, "$type") {
-			es = append(es, fmt.Errorf("the %q is not allowed as tag name", k))
-		}
-	}
-
-	return ws, es
-}
-
 func expandTags(tagsMap map[string]interface{}) map[string]*string {
 	output := make(map[string]*string, len(tagsMap))