diff --git a/cmd/prometheus/main.go b/cmd/prometheus/main.go
index 214ba7d75..f8d8aa993 100644
--- a/cmd/prometheus/main.go
+++ b/cmd/prometheus/main.go
@@ -170,7 +170,7 @@ type Reloadable interface {
 func reloadConfig(filename string, rls ...Reloadable) bool {
 	log.Infof("Loading configuration file %s", filename)
 
-	conf, err := config.LoadFromFile(filename)
+	conf, err := config.LoadFile(filename)
 	if err != nil {
 		log.Errorf("Couldn't load configuration (-config.file=%s): %v", filename, err)
 		log.Errorf("Note: The configuration format has changed with version 0.14. Please see the documentation (http://prometheus.io/docs/operating/configuration/) and the provided configuration migration tool (https://github.com/prometheus/migrate).")
diff --git a/cmd/promtool/main.go b/cmd/promtool/main.go
index 791fa069f..b630b6166 100644
--- a/cmd/promtool/main.go
+++ b/cmd/promtool/main.go
@@ -22,8 +22,6 @@ import (
 	"strings"
 	"text/template"
 
-	"gopkg.in/yaml.v2"
-
 	"github.com/prometheus/prometheus/config"
 	"github.com/prometheus/prometheus/promql"
 	"github.com/prometheus/prometheus/util/cli"
@@ -73,32 +71,53 @@ func checkConfig(t cli.Term, filename string) ([]string, error) {
 		return nil, fmt.Errorf("is a directory")
 	}
 
-	content, err := ioutil.ReadFile(filename)
+	cfg, err := config.LoadFile(filename)
 	if err != nil {
 		return nil, err
 	}
 
-	var cfg config.Config
-	if err := yaml.Unmarshal(content, &cfg); err != nil {
-		return nil, err
+	check := func(fn string) error {
+		// Nothing set, nothing to error on.
+		if fn == "" {
+			return nil
+		}
+		_, err := os.Stat(fn)
+		return err
 	}
+
 	var ruleFiles []string
 	for _, rf := range cfg.RuleFiles {
-		if !filepath.IsAbs(rf) {
-			rf = filepath.Join(filepath.Dir(filename), rf)
-		}
-
 		rfs, err := filepath.Glob(rf)
 		if err != nil {
 			return nil, err
 		}
-		// If an explicit file was given, error if it doesn't exist.
-		if !strings.Contains(rf, "*") && len(rfs) == 0 {
-			return nil, fmt.Errorf("%q does not point to an existing file", rf)
+		// If an explicit file was given, error if it is not accessible.
+		if !strings.Contains(rf, "*") {
+			if len(rfs) == 0 {
+				return nil, fmt.Errorf("%q does not point to an existing file", rf)
+			}
+			if err := check(rfs[0]); err != nil {
+				return nil, fmt.Errorf("error checking rule file %q: %s", rfs[0], err)
+			}
 		}
 		ruleFiles = append(ruleFiles, rfs...)
 	}
 
+	for _, scfg := range cfg.ScrapeConfigs {
+		if err := check(scfg.BearerTokenFile); err != nil {
+			return nil, fmt.Errorf("error checking bearer token file %q: %s", scfg.BearerTokenFile, err)
+		}
+
+		if scfg.ClientCert != nil {
+			if err := check(scfg.ClientCert.Cert); err != nil {
+				return nil, fmt.Errorf("error checking client cert file %q: %s", scfg.ClientCert.Cert, err)
+			}
+			if err := check(scfg.ClientCert.Key); err != nil {
+				return nil, fmt.Errorf("error checking client key file %q: %s", scfg.ClientCert.Key, err)
+			}
+		}
+	}
+
 	return ruleFiles, nil
 }
 
diff --git a/config/config.go b/config/config.go
index dc0fdca7e..34b9362c8 100644
--- a/config/config.go
+++ b/config/config.go
@@ -40,8 +40,8 @@ func Load(s string) (*Config, error) {
 	return cfg, nil
 }
 
-// LoadFromFile parses the given YAML file into a Config.
-func LoadFromFile(filename string) (*Config, error) {
+// LoadFile parses the given YAML file into a Config.
+func LoadFile(filename string) (*Config, error) {
 	content, err := ioutil.ReadFile(filename)
 	if err != nil {
 		return nil, err
diff --git a/config/config_test.go b/config/config_test.go
index 5284699fa..16ab2c604 100644
--- a/config/config_test.go
+++ b/config/config_test.go
@@ -181,11 +181,11 @@ var expectedConf = &Config{
 func TestLoadConfig(t *testing.T) {
 	// Parse a valid file that sets a global scrape timeout. This tests whether parsing
 	// an overwritten default field in the global config permanently changes the default.
-	if _, err := LoadFromFile("testdata/global_timeout.good.yml"); err != nil {
+	if _, err := LoadFile("testdata/global_timeout.good.yml"); err != nil {
 		t.Errorf("Error parsing %s: %s", "testdata/conf.good.yml", err)
 	}
 
-	c, err := LoadFromFile("testdata/conf.good.yml")
+	c, err := LoadFile("testdata/conf.good.yml")
 	if err != nil {
 		t.Fatalf("Error parsing %s: %s", "testdata/conf.good.yml", err)
 	}
@@ -252,7 +252,7 @@ var expectedErrors = []struct {
 
 func TestBadConfigs(t *testing.T) {
 	for _, ee := range expectedErrors {
-		_, err := LoadFromFile("testdata/" + ee.filename)
+		_, err := LoadFile("testdata/" + ee.filename)
 		if err == nil {
 			t.Errorf("Expected error parsing %s but got none", ee.filename)
 			continue