diff --git a/cmd/promtool/main.go b/cmd/promtool/main.go
index 22e7d16ff..9b436ff71 100644
--- a/cmd/promtool/main.go
+++ b/cmd/promtool/main.go
@@ -44,13 +44,16 @@ import (
 	yaml "gopkg.in/yaml.v2"
 
 	"github.com/prometheus/prometheus/config"
+	"github.com/prometheus/prometheus/discovery"
 	"github.com/prometheus/prometheus/discovery/file"
 	_ "github.com/prometheus/prometheus/discovery/install" // Register service discovery implementations.
 	"github.com/prometheus/prometheus/discovery/kubernetes"
 	"github.com/prometheus/prometheus/discovery/targetgroup"
+	"github.com/prometheus/prometheus/notifier"
 	"github.com/prometheus/prometheus/pkg/labels"
 	"github.com/prometheus/prometheus/pkg/rulefmt"
 	"github.com/prometheus/prometheus/promql"
+	"github.com/prometheus/prometheus/scrape"
 )
 
 func main() {
@@ -363,19 +366,60 @@ func checkConfig(filename string) ([]string, error) {
 					}
 					if len(files) != 0 {
 						for _, f := range files {
-							err = checkSDFile(f)
+							var targetGroups []*targetgroup.Group
+							targetGroups, err = checkSDFile(f)
 							if err != nil {
 								return nil, errors.Errorf("checking SD file %q: %v", file, err)
 							}
+							if err := checkTargetGroupsForScrapeConfig(targetGroups, scfg); err != nil {
+								return nil, err
+							}
 						}
 						continue
 					}
 					fmt.Printf("  WARNING: file %q for file_sd in scrape job %q does not exist\n", file, scfg.JobName)
 				}
+			case discovery.StaticConfig:
+				if err := checkTargetGroupsForScrapeConfig(c, scfg); err != nil {
+					return nil, err
+				}
 			}
 		}
 	}
 
+	alertConfig := cfg.AlertingConfig
+	for _, amcfg := range alertConfig.AlertmanagerConfigs {
+		for _, c := range amcfg.ServiceDiscoveryConfigs {
+			switch c := c.(type) {
+			case *file.SDConfig:
+				for _, file := range c.Files {
+					files, err := filepath.Glob(file)
+					if err != nil {
+						return nil, err
+					}
+					if len(files) != 0 {
+						for _, f := range files {
+							var targetGroups []*targetgroup.Group
+							targetGroups, err = checkSDFile(f)
+							if err != nil {
+								return nil, errors.Errorf("checking SD file %q: %v", file, err)
+							}
+
+							if err := checkTargetGroupsForAlertmanager(targetGroups, amcfg); err != nil {
+								return nil, err
+							}
+						}
+						continue
+					}
+					fmt.Printf("  WARNING: file %q for file_sd in alertmanager config does not exist\n", file)
+				}
+			case discovery.StaticConfig:
+				if err := checkTargetGroupsForAlertmanager(c, amcfg); err != nil {
+					return nil, err
+				}
+			}
+		}
+	}
 	return ruleFiles, nil
 }
 
@@ -397,16 +441,16 @@ func checkTLSConfig(tlsConfig config_util.TLSConfig) error {
 	return nil
 }
 
-func checkSDFile(filename string) error {
+func checkSDFile(filename string) ([]*targetgroup.Group, error) {
 	fd, err := os.Open(filename)
 	if err != nil {
-		return err
+		return nil, err
 	}
 	defer fd.Close()
 
 	content, err := ioutil.ReadAll(fd)
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	var targetGroups []*targetgroup.Group
@@ -414,23 +458,23 @@ func checkSDFile(filename string) error {
 	switch ext := filepath.Ext(filename); strings.ToLower(ext) {
 	case ".json":
 		if err := json.Unmarshal(content, &targetGroups); err != nil {
-			return err
+			return nil, err
 		}
 	case ".yml", ".yaml":
 		if err := yaml.UnmarshalStrict(content, &targetGroups); err != nil {
-			return err
+			return nil, err
 		}
 	default:
-		return errors.Errorf("invalid file extension: %q", ext)
+		return nil, errors.Errorf("invalid file extension: %q", ext)
 	}
 
 	for i, tg := range targetGroups {
 		if tg == nil {
-			return errors.Errorf("nil target group item found (index %d)", i)
+			return nil, errors.Errorf("nil target group item found (index %d)", i)
 		}
 	}
 
-	return nil
+	return targetGroups, nil
 }
 
 // CheckRules validates rule files.
@@ -981,3 +1025,25 @@ func importRules(url *url.URL, start, end, outputDir string, evalInterval time.D
 
 	return nil
 }
+
+func checkTargetGroupsForAlertmanager(targetGroups []*targetgroup.Group, amcfg *config.AlertmanagerConfig) error {
+	for _, tg := range targetGroups {
+		if _, _, err := notifier.AlertmanagerFromGroup(tg, amcfg); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func checkTargetGroupsForScrapeConfig(targetGroups []*targetgroup.Group, scfg *config.ScrapeConfig) error {
+	for _, tg := range targetGroups {
+		_, failures := scrape.TargetsFromGroup(tg, scfg)
+		if len(failures) > 0 {
+			first := failures[0]
+			return first
+		}
+	}
+
+	return nil
+}
diff --git a/cmd/promtool/main_test.go b/cmd/promtool/main_test.go
index 87ac13e76..8ca078cc5 100644
--- a/cmd/promtool/main_test.go
+++ b/cmd/promtool/main_test.go
@@ -111,7 +111,7 @@ func TestCheckSDFile(t *testing.T) {
 	}
 	for _, test := range cases {
 		t.Run(test.name, func(t *testing.T) {
-			err := checkSDFile(test.file)
+			_, err := checkSDFile(test.file)
 			if test.err != "" {
 				require.Equalf(t, test.err, err.Error(), "Expected error %q, got %q", test.err, err.Error())
 				return
@@ -163,3 +163,42 @@ func BenchmarkCheckDuplicates(b *testing.B) {
 		checkDuplicates(rgs.Groups)
 	}
 }
+
+func TestCheckTargetConfig(t *testing.T) {
+	cases := []struct {
+		name string
+		file string
+		err  string
+	}{
+		{
+			name: "url_in_scrape_targetgroup_with_relabel_config.good",
+			file: "url_in_scrape_targetgroup_with_relabel_config.good.yml",
+			err:  "",
+		},
+		{
+			name: "url_in_alert_targetgroup_with_relabel_config.good",
+			file: "url_in_alert_targetgroup_with_relabel_config.good.yml",
+			err:  "",
+		},
+		{
+			name: "url_in_scrape_targetgroup_with_relabel_config.bad",
+			file: "url_in_scrape_targetgroup_with_relabel_config.bad.yml",
+			err:  "instance 0 in group 0: \"http://bad\" is not a valid hostname",
+		},
+		{
+			name: "url_in_alert_targetgroup_with_relabel_config.bad",
+			file: "url_in_alert_targetgroup_with_relabel_config.bad.yml",
+			err:  "\"http://bad\" is not a valid hostname",
+		},
+	}
+	for _, test := range cases {
+		t.Run(test.name, func(t *testing.T) {
+			_, err := checkConfig("testdata/" + test.file)
+			if test.err != "" {
+				require.Equalf(t, test.err, err.Error(), "Expected error %q, got %q", test.err, err.Error())
+				return
+			}
+			require.NoError(t, err)
+		})
+	}
+}
diff --git a/cmd/promtool/testdata/url_in_alert_targetgroup_with_relabel_config.bad.yml b/cmd/promtool/testdata/url_in_alert_targetgroup_with_relabel_config.bad.yml
new file mode 100644
index 000000000..a23628e18
--- /dev/null
+++ b/cmd/promtool/testdata/url_in_alert_targetgroup_with_relabel_config.bad.yml
@@ -0,0 +1,8 @@
+alerting:
+  alertmanagers:
+    - relabel_configs:
+        - source_labels: [__address__]
+          target_label: __param_target
+      static_configs:
+        - targets:
+            - http://bad
diff --git a/cmd/promtool/testdata/url_in_alert_targetgroup_with_relabel_config.good.yml b/cmd/promtool/testdata/url_in_alert_targetgroup_with_relabel_config.good.yml
new file mode 100644
index 000000000..575fe5f11
--- /dev/null
+++ b/cmd/promtool/testdata/url_in_alert_targetgroup_with_relabel_config.good.yml
@@ -0,0 +1,10 @@
+alerting:
+  alertmanagers:
+    - relabel_configs:
+        - source_labels: [__address__]
+          target_label: __param_target
+        - target_label: __address__
+          replacement: good
+      static_configs:
+        - targets:
+            - http://bad
diff --git a/cmd/promtool/testdata/url_in_scrape_targetgroup_with_relabel_config.bad.yml b/cmd/promtool/testdata/url_in_scrape_targetgroup_with_relabel_config.bad.yml
new file mode 100644
index 000000000..d5daf6e9b
--- /dev/null
+++ b/cmd/promtool/testdata/url_in_scrape_targetgroup_with_relabel_config.bad.yml
@@ -0,0 +1,8 @@
+scrape_configs:
+  - job_name: prometheus
+    relabel_configs:
+      - source_labels: [__address__]
+        target_label: __param_target
+    static_configs:
+      - targets:
+          - http://bad
diff --git a/cmd/promtool/testdata/url_in_scrape_targetgroup_with_relabel_config.good.yml b/cmd/promtool/testdata/url_in_scrape_targetgroup_with_relabel_config.good.yml
new file mode 100644
index 000000000..ab26f00ed
--- /dev/null
+++ b/cmd/promtool/testdata/url_in_scrape_targetgroup_with_relabel_config.good.yml
@@ -0,0 +1,10 @@
+scrape_configs:
+  - job_name: prometheus
+    relabel_configs:
+      - source_labels: [__address__]
+        target_label: __param_target
+      - target_label: __address__
+        replacement: good
+    static_configs:
+      - targets:
+          - http://good
diff --git a/notifier/notifier.go b/notifier/notifier.go
index 97086d562..19a7f0bf9 100644
--- a/notifier/notifier.go
+++ b/notifier/notifier.go
@@ -602,7 +602,7 @@ func (n *Manager) Stop() {
 	n.cancel()
 }
 
-// alertmanager holds Alertmanager endpoint information.
+// Alertmanager holds Alertmanager endpoint information.
 type alertmanager interface {
 	url() *url.URL
 }
@@ -654,7 +654,7 @@ func (s *alertmanagerSet) sync(tgs []*targetgroup.Group) {
 	allDroppedAms := []alertmanager{}
 
 	for _, tg := range tgs {
-		ams, droppedAms, err := alertmanagerFromGroup(tg, s.cfg)
+		ams, droppedAms, err := AlertmanagerFromGroup(tg, s.cfg)
 		if err != nil {
 			level.Error(s.logger).Log("msg", "Creating discovered Alertmanagers failed", "err", err)
 			continue
@@ -691,9 +691,9 @@ func postPath(pre string, v config.AlertmanagerAPIVersion) string {
 	return path.Join("/", pre, alertPushEndpoint)
 }
 
-// alertmanagerFromGroup extracts a list of alertmanagers from a target group
+// AlertmanagerFromGroup extracts a list of alertmanagers from a target group
 // and an associated AlertmanagerConfig.
-func alertmanagerFromGroup(tg *targetgroup.Group, cfg *config.AlertmanagerConfig) ([]alertmanager, []alertmanager, error) {
+func AlertmanagerFromGroup(tg *targetgroup.Group, cfg *config.AlertmanagerConfig) ([]alertmanager, []alertmanager, error) {
 	var res []alertmanager
 	var droppedAlertManagers []alertmanager
 
diff --git a/notifier/notifier_test.go b/notifier/notifier_test.go
index e4a7f26cd..b04b07e94 100644
--- a/notifier/notifier_test.go
+++ b/notifier/notifier_test.go
@@ -447,7 +447,7 @@ func (a alertmanagerMock) url() *url.URL {
 
 func TestLabelSetNotReused(t *testing.T) {
 	tg := makeInputTargetGroup()
-	_, _, err := alertmanagerFromGroup(tg, &config.AlertmanagerConfig{})
+	_, _, err := AlertmanagerFromGroup(tg, &config.AlertmanagerConfig{})
 
 	require.NoError(t, err)
 
diff --git a/scrape/scrape.go b/scrape/scrape.go
index e981ad36a..590133cde 100644
--- a/scrape/scrape.go
+++ b/scrape/scrape.go
@@ -472,7 +472,7 @@ func (sp *scrapePool) Sync(tgs []*targetgroup.Group) {
 	var all []*Target
 	sp.droppedTargets = []*Target{}
 	for _, tg := range tgs {
-		targets, failures := targetsFromGroup(tg, sp.config)
+		targets, failures := TargetsFromGroup(tg, sp.config)
 		for _, err := range failures {
 			level.Error(sp.logger).Log("msg", "Creating target failed", "err", err)
 		}
diff --git a/scrape/target.go b/scrape/target.go
index 35d691751..c791a8a22 100644
--- a/scrape/target.go
+++ b/scrape/target.go
@@ -469,8 +469,8 @@ func populateLabels(lset labels.Labels, cfg *config.ScrapeConfig) (res, orig lab
 	return res, preRelabelLabels, nil
 }
 
-// targetsFromGroup builds targets based on the given TargetGroup and config.
-func targetsFromGroup(tg *targetgroup.Group, cfg *config.ScrapeConfig) ([]*Target, []error) {
+// TargetsFromGroup builds targets based on the given TargetGroup and config.
+func TargetsFromGroup(tg *targetgroup.Group, cfg *config.ScrapeConfig) ([]*Target, []error) {
 	targets := make([]*Target, 0, len(tg.Targets))
 	failures := []error{}
 
diff --git a/scrape/target_test.go b/scrape/target_test.go
index 542326d7c..fa03c068e 100644
--- a/scrape/target_test.go
+++ b/scrape/target_test.go
@@ -371,7 +371,7 @@ func TestNewClientWithBadTLSConfig(t *testing.T) {
 func TestTargetsFromGroup(t *testing.T) {
 	expectedError := "instance 0 in group : no address"
 
-	targets, failures := targetsFromGroup(&targetgroup.Group{Targets: []model.LabelSet{{}, {model.AddressLabel: "localhost:9090"}}}, &config.ScrapeConfig{})
+	targets, failures := TargetsFromGroup(&targetgroup.Group{Targets: []model.LabelSet{{}, {model.AddressLabel: "localhost:9090"}}}, &config.ScrapeConfig{})
 	if len(targets) != 1 {
 		t.Fatalf("Expected 1 target, got %v", len(targets))
 	}