diff --git a/Makefile b/Makefile
index 80449f0..ce30363 100644
--- a/Makefile
+++ b/Makefile
@@ -20,6 +20,7 @@ generate: build
 		./tests/reference_to_pointer.go \
 		./tests/html.go \
 		./tests/unknown_fields.go \
+		./tests/type_declaration.go
 
 	bin/easyjson -all ./tests/data.go
 	bin/easyjson -all ./tests/nothing.go
@@ -36,6 +37,7 @@ generate: build
 	bin/easyjson ./tests/key_marshaler_map.go
 	bin/easyjson -disallow_unknown_fields ./tests/disallow_unknown.go
 	bin/easyjson ./tests/unknown_fields.go
+	bin/easyjson ./tests/type_declaration.go
 
 test: generate
 	go test \
diff --git a/parser/parser.go b/parser/parser.go
index 6f7cc22..1aa42d7 100644
--- a/parser/parser.go
+++ b/parser/parser.go
@@ -22,8 +22,7 @@ type Parser struct {
 type visitor struct {
 	*Parser
 
-	name     string
-	explicit bool
+	name string
 }
 
 func (p *Parser) needType(comments string) bool {
@@ -44,20 +43,33 @@ func (v *visitor) Visit(n ast.Node) (w ast.Visitor) {
 		return v
 
 	case *ast.GenDecl:
-		v.explicit = v.needType(n.Doc.Text())
-
-		if !v.explicit && !v.AllStructs {
-			return nil
+		explicit := v.needType(n.Doc.Text())
+		if !explicit {
+			return v
 		}
+
+		for _, nc := range n.Specs {
+			switch nct := nc.(type) {
+			case *ast.TypeSpec:
+				nct.Doc = n.Doc
+			}
+		}
+
 		return v
 	case *ast.TypeSpec:
+		explicit := v.needType(n.Doc.Text())
+		if !explicit && !v.AllStructs {
+			return nil
+		}
+
 		v.name = n.Name.String()
 
 		// Allow to specify non-structs explicitly independent of '-all' flag.
-		if v.explicit {
+		if explicit {
 			v.StructNames = append(v.StructNames, v.name)
 			return nil
 		}
+
 		return v
 	case *ast.StructType:
 		v.StructNames = append(v.StructNames, v.name)
diff --git a/tests/basic_test.go b/tests/basic_test.go
index 938add0..004d278 100644
--- a/tests/basic_test.go
+++ b/tests/basic_test.go
@@ -53,6 +53,9 @@ var testCases = []struct {
 	{&myUInt8SliceValue, myUInt8SliceString},
 	{&myUInt8ArrayValue, myUInt8ArrayString},
 	{&mapWithEncodingMarshaler, mapWithEncodingMarshalerString},
+	{&myGenDeclaredValue, myGenDeclaredString},
+	{&myGenDeclaredWithCommentValue, myGenDeclaredWithCommentString},
+	{&myTypeDeclaredValue, myTypeDeclaredString},
 }
 
 func TestMarshal(t *testing.T) {
@@ -243,3 +246,22 @@ func TestDisallowUnknown(t *testing.T) {
 		t.Error("want error, got nil")
 	}
 }
+
+var testNotGeneratedTypeCases = []interface{}{
+	TypeNotDeclared{},
+}
+
+func TestMethodsNoGenerated(t *testing.T) {
+	var ok bool
+	for i, instance := range testNotGeneratedTypeCases {
+		_, ok = instance.(json.Marshaler)
+		if ok {
+			t.Errorf("[%d, %T] Unexpected MarshalJSON()", i, instance)
+		}
+
+		_, ok = instance.(json.Unmarshaler)
+		if ok {
+			t.Errorf("[%d, %T] Unexpected Unmarshaler()", i, instance)
+		}
+	}
+}
diff --git a/tests/type_declaration.go b/tests/type_declaration.go
new file mode 100644
index 0000000..e638455
--- /dev/null
+++ b/tests/type_declaration.go
@@ -0,0 +1,33 @@
+package tests
+
+//easyjson:json
+type (
+	GenDeclared1 struct {
+		Value string
+	}
+
+	// A gen declared easyjson struct with a comment
+	GenDeclaredWithComment struct {
+		Value string
+	}
+)
+
+type (
+	//easyjson:json
+	TypeDeclared struct {
+		Value string
+	}
+
+	TypeNotDeclared struct {
+		Value string
+	}
+)
+
+var (
+	myGenDeclaredValue             = TypeDeclared{Value: "GenDeclared"}
+	myGenDeclaredString            = `{"Value":"GenDeclared"}`
+	myGenDeclaredWithCommentValue  = TypeDeclared{Value: "GenDeclaredWithComment"}
+	myGenDeclaredWithCommentString = `{"Value":"GenDeclaredWithComment"}`
+	myTypeDeclaredValue            = TypeDeclared{Value: "TypeDeclared"}
+	myTypeDeclaredString           = `{"Value":"TypeDeclared"}`
+)