diff --git a/features/features.go b/features/features.go
index df51a40af12..a9fb8e1fa5b 100644
--- a/features/features.go
+++ b/features/features.go
@@ -97,10 +97,16 @@ func (f SnapdFeature) IsExported() bool {
 // Snapd considers the feature enabled if the file is present.
 // The contents of the file are not important.
 func (f SnapdFeature) ControlFile() string {
+	if !f.IsExported() {
+		panic(fmt.Sprintf("cannot compute the control file of feature %q because that feature is not exported", f))
+	}
 	return filepath.Join(dirs.FeaturesDir, f.String())
 }
 
-// IsEnabled checks if a given snapd feature is enabled.
+// IsEnabled checks if a given exported snapd feature is enabled.
 func (f SnapdFeature) IsEnabled() bool {
+	if !f.IsExported() {
+		panic(fmt.Sprintf("cannot check if feature %q is enabled because that feature is not exported", f))
+	}
 	return osutil.FileExists(f.ControlFile())
 }
diff --git a/features/features_test.go b/features/features_test.go
index a6a0b9f7716..8b0397d545e 100644
--- a/features/features_test.go
+++ b/features/features_test.go
@@ -74,6 +74,9 @@ func (*featureSuite) TestIsEnabled(c *C) {
 	err = ioutil.WriteFile(filepath.Join(dirs.FeaturesDir, f.String()), nil, 0644)
 	c.Assert(err, IsNil)
 	c.Check(f.IsEnabled(), Equals, true)
+
+	// Features that are not exported cannot be queried.
+	c.Check(features.Layouts.IsEnabled, PanicMatches, `cannot check if feature "layouts" is enabled because that feature is not exported`)
 }
 
 func (*featureSuite) TestIsEnabledByDefault(c *C) {
@@ -85,5 +88,7 @@ func (*featureSuite) TestIsEnabledByDefault(c *C) {
 }
 
 func (*featureSuite) TestControlFile(c *C) {
-	c.Check(features.Layouts.ControlFile(), Equals, "/var/lib/snapd/features/layouts")
+	c.Check(features.PerUserMountNamespace.ControlFile(), Equals, "/var/lib/snapd/features/per-user-mount-namespace")
+	// Features that are not exported don't have a control file.
+	c.Check(features.Layouts.ControlFile, PanicMatches, `cannot compute the control file of feature "layouts" because that feature is not exported`)
 }