diff --git a/oas.go b/oas.go
index 94e1d34..c59226a 100644
--- a/oas.go
+++ b/oas.go
@@ -144,6 +144,7 @@ type SchemaObject struct {
 	Items       *SchemaObject          `json:"items,omitempty"` // use ptr to prevent recursive error
 	Example     interface{}            `json:"example,omitempty"`
 	Deprecated  bool                   `json:"deprecated,omitempty"`
+	Nullable    bool                   `json:"nullable,omitempty"`
 
 	// Ref is used when SchemaObject is as a ReferenceObject
 	Ref string `json:"$ref,omitempty"`
@@ -170,7 +171,6 @@ type SchemaObject struct {
 	// AdditionalProperties
 	// Description
 	// Default
-	// Nullable
 	// ReadOnly
 	// WriteOnly
 	// XML
diff --git a/parser.go b/parser.go
index 402eb57..ad6ad0c 100644
--- a/parser.go
+++ b/parser.go
@@ -1150,6 +1150,19 @@ astFieldsLoop:
 					fieldSchema.Deprecated = true
 					continue astFieldsLoop
 				}
+				if kv := strings.Split(v, "="); len(kv) == 2 {
+					switch kv[0] {
+					case "type":
+						fieldSchema.Type = kv[1]
+						fieldSchema.Ref = ""
+
+					case "format":
+						fieldSchema.Format = kv[1]
+
+					case "nullable":
+						fieldSchema.Nullable, _ = strconv.ParseBool(kv[1])
+					}
+				}
 			}
 
 			if tag := astFieldTag.Get("json"); tag != "" {