diff --git a/php/ext/google/protobuf/def.c b/php/ext/google/protobuf/def.c
index 018dac19ac..8c3266eb07 100644
--- a/php/ext/google/protobuf/def.c
+++ b/php/ext/google/protobuf/def.c
@@ -456,6 +456,44 @@ PHP_METHOD(FieldDescriptor, getEnumType) {
   RETURN_COPY_VALUE(&ret);
 }
 
+/*
+ * FieldDescriptor::getContainingOneof()
+ *
+ * Returns the OneofDescriptor for this field, or null if it is not inside
+ * a oneof.
+ */
+PHP_METHOD(FieldDescriptor, getContainingOneof) {
+  FieldDescriptor *intern = (FieldDescriptor*)Z_OBJ_P(getThis());
+  const upb_OneofDef *o = upb_FieldDef_ContainingOneof(intern->fielddef);
+  zval ret;
+
+  if (!o) {
+    RETURN_NULL();
+  }
+
+  OneofDescriptor_FromOneofDef(&ret, o);
+  RETURN_COPY_VALUE(&ret);
+}
+
+/*
+ * FieldDescriptor::getRealContainingOneof()
+ *
+ * Returns the non-synthetic OneofDescriptor for this field, or null if it is
+ * not inside a oneof.
+ */
+PHP_METHOD(FieldDescriptor, getRealContainingOneof) {
+  FieldDescriptor *intern = (FieldDescriptor*)Z_OBJ_P(getThis());
+  const upb_OneofDef *o = upb_FieldDef_RealContainingOneof(intern->fielddef);
+  zval ret;
+
+  if (!o) {
+    RETURN_NULL();
+  }
+
+  OneofDescriptor_FromOneofDef(&ret, o);
+  RETURN_COPY_VALUE(&ret);
+}
+
 /*
  * FieldDescriptor::getMessageType()
  *
@@ -482,6 +520,8 @@ static zend_function_entry FieldDescriptor_methods[] = {
   PHP_ME(FieldDescriptor, getType,   arginfo_void, ZEND_ACC_PUBLIC)
   PHP_ME(FieldDescriptor, isMap,     arginfo_void, ZEND_ACC_PUBLIC)
   PHP_ME(FieldDescriptor, getEnumType, arginfo_void, ZEND_ACC_PUBLIC)
+  PHP_ME(FieldDescriptor, getContainingOneof, arginfo_void, ZEND_ACC_PUBLIC)
+  PHP_ME(FieldDescriptor, getRealContainingOneof, arginfo_void, ZEND_ACC_PUBLIC)
   PHP_ME(FieldDescriptor, getMessageType, arginfo_void, ZEND_ACC_PUBLIC)
   ZEND_FE_END
 };
@@ -516,6 +556,7 @@ static zend_class_entry *Descriptor_GetGeneratedClass(const upb_MessageDef *m) {
   char *classname =
     GetPhpClassname(upb_MessageDef_File(m), upb_MessageDef_FullName(m), false);
   zend_error(E_ERROR, "Couldn't load generated class %s", classname);
+  return NULL;
 }
 
 void Descriptor_FromMessageDef(zval *val, const upb_MessageDef *m) {
diff --git a/php/tests/DescriptorsTest.php b/php/tests/DescriptorsTest.php
index 4f17a49571..336d979428 100644
--- a/php/tests/DescriptorsTest.php
+++ b/php/tests/DescriptorsTest.php
@@ -83,10 +83,10 @@ class DescriptorsTest extends TestBase
         $this->assertSame($class, $desc->getClass());
 
         $this->assertInstanceOf('\Google\Protobuf\FieldDescriptor', $desc->getField(0));
-        $this->assertSame(7, $desc->getFieldCount());
+        $this->assertSame(8, $desc->getFieldCount());
 
         $this->assertInstanceOf('\Google\Protobuf\OneofDescriptor', $desc->getOneofDecl(0));
-        $this->assertSame(1, $desc->getOneofDeclCount());
+        $this->assertSame(2, $desc->getOneofDeclCount());
     }
 
     public function testDescriptorForIncludedMessage()
@@ -180,6 +180,7 @@ class DescriptorsTest extends TestBase
         $this->assertSame(self::GPBTYPE_MESSAGE, $fieldDesc->getType());
         $this->assertInstanceOf('\Google\Protobuf\Descriptor', $fieldDesc->getMessageType());
         $this->assertFalse($fieldDesc->isMap());
+        $this->assertNull($fieldDesc->getContainingOneof());
 
         // Oneof int field
         // Tested further in testOneofDescriptor()
@@ -189,6 +190,21 @@ class DescriptorsTest extends TestBase
         $this->assertSame(self::GPBLABEL_OPTIONAL, $fieldDesc->getLabel());
         $this->assertSame(self::GPBTYPE_INT32, $fieldDesc->getType());
         $this->assertFalse($fieldDesc->isMap());
+        $this->assertSame($fieldDesc->getContainingOneof(), $fieldDesc->getRealContainingOneof());
+
+        $oneofDesc = $fieldDesc->getContainingOneof();
+        $this->assertSame('my_oneof', $oneofDesc->getName());
+
+        // Proto3 optional it field.
+        // Tested further in testOneofDescriptor()
+        $fieldDesc = $fieldDescMap[52];
+        $this->assertSame('proto3_optional_int32', $fieldDesc->getName());
+        $this->assertSame(52, $fieldDesc->getNumber());
+        $this->assertSame(self::GPBLABEL_OPTIONAL, $fieldDesc->getLabel());
+        $this->assertSame(self::GPBTYPE_INT32, $fieldDesc->getType());
+        $this->assertFalse($fieldDesc->isMap());
+        $this->assertNull($fieldDesc->getRealContainingOneof());
+        $this->assertNotNull($fieldDesc->getContainingOneof());
 
         // Map int-enum field
         $fieldDesc = $fieldDescMap[71];
diff --git a/php/tests/proto/test_descriptors.proto b/php/tests/proto/test_descriptors.proto
index d42aec7cec..b0956c6edd 100644
--- a/php/tests/proto/test_descriptors.proto
+++ b/php/tests/proto/test_descriptors.proto
@@ -14,6 +14,7 @@ message TestDescriptorsMessage {
   oneof my_oneof {
     int32 oneof_int32    = 51;
   }
+  optional int32 proto3_optional_int32 = 52;
 
   map<int32, EnumSub> map_int32_enum = 71;