diff --git a/lokerpc/schema.go b/lokerpc/schema.go
index 6a80844..cc42ac2 100644
--- a/lokerpc/schema.go
+++ b/lokerpc/schema.go
@@ -54,6 +54,11 @@ func TypeSchema(t reflect.Type, tdefs map[reflect.Type]*NamedSchema) *jtd.Schema
 
 			for i := 0; i < t.NumField(); i++ {
 				f := t.Field(i)
+
+				if !f.IsExported() {
+					continue
+				}
+
 				name, omit := parseTag(f.Tag.Get("json"))
 				if name == "" {
 					name = f.Name
diff --git a/lokerpc/schema_test.go b/lokerpc/schema_test.go
index 81b44df..02c5f78 100644
--- a/lokerpc/schema_test.go
+++ b/lokerpc/schema_test.go
@@ -24,7 +24,8 @@ func (textMarshaler) MarshalText() ([]byte, error) {
 
 func TestTypeSchema(t *testing.T) {
 	type NamedStruct struct {
-		Foo string `json:"foo"`
+		Foo  string `json:"foo"`
+		nope string
 	}
 
 	// Name to conflict with flag.Flag