diff --git a/binding/format/protobuf/v2/pb/cloudevent.pb.go b/binding/format/protobuf/v2/pb/cloudevent.pb.go
index 587e634cf..d823f07e2 100644
--- a/binding/format/protobuf/v2/pb/cloudevent.pb.go
+++ b/binding/format/protobuf/v2/pb/cloudevent.pb.go
@@ -23,7 +23,7 @@ const (
 )
 
 // CloudEvent is copied from
-// https://github.com/cloudevents/spec/blob/master/protobuf-format.md.
+// https://github.com/cloudevents/spec/blob/main/cloudevents/formats/protobuf-format.md.
 type CloudEvent struct {
 	state         protoimpl.MessageState
 	sizeCache     protoimpl.SizeCache
diff --git a/binding/format/protobuf/v2/pb/cloudevent.proto b/binding/format/protobuf/v2/pb/cloudevent.proto
index 29a7fd6fd..a68237419 100644
--- a/binding/format/protobuf/v2/pb/cloudevent.proto
+++ b/binding/format/protobuf/v2/pb/cloudevent.proto
@@ -8,7 +8,7 @@ import "google/protobuf/any.proto";
 import "google/protobuf/timestamp.proto";
 
 // CloudEvent is copied from
-// https://github.com/cloudevents/spec/blob/master/protobuf-format.md.
+// https://github.com/cloudevents/spec/blob/main/cloudevents/formats/protobuf-format.md.
 message CloudEvent {
   // Unique event identifier.
   string id = 1;
diff --git a/docs/concepts.md b/docs/concepts.md
index cba55fd8b..901c787f2 100644
--- a/docs/concepts.md
+++ b/docs/concepts.md
@@ -56,13 +56,13 @@ support the following:
 
 ## Personas
 
-- [Producer](https://github.com/cloudevents/spec/blob/master/spec.md#producer),
+- [Producer](https://github.com/cloudevents/spec/blob/main/cloudevents/spec.md#producer),
   the "producer" is a specific instance, process or device that creates the data
   structure describing the CloudEvent.
-- [Consumer](https://github.com/cloudevents/spec/blob/master/spec.md#consumer),
+- [Consumer](https://github.com/cloudevents/spec/blob/main/cloudevents/spec.md#consumer),
   a "consumer" receives the event and acts upon it. It uses the context and data
   to execute some logic, which might lead to the occurrence of new events.
-- [Intermediary](https://github.com/cloudevents/spec/blob/master/spec.md#intermediary),
+- [Intermediary](https://github.com/cloudevents/spec/blob/main/cloudevents/spec.md#intermediary),
   An "intermediary" receives a message containing an event for the purpose of
   forwarding it to the next receiver, which might be another intermediary or a
   Consumer. A typical task for an intermediary is to route the event to
@@ -96,4 +96,4 @@ continued the message to one or more Consumers.
 Mutator, when a Producer or Intermediary blocks on a response from a Consumer,
 replacing the original Event.
 
-![mutator](./images/mutator.svg "Mutator")
\ No newline at end of file
+![mutator](./images/mutator.svg "Mutator")
diff --git a/v2/binding/encoding.go b/v2/binding/encoding.go
index 5070b7295..bb8f91424 100644
--- a/v2/binding/encoding.go
+++ b/v2/binding/encoding.go
@@ -11,9 +11,9 @@ import "errors"
 type Encoding int
 
 const (
-	// Binary encoding as specified in https://github.com/cloudevents/spec/blob/master/spec.md#message
+	// Binary encoding as specified in https://github.com/cloudevents/spec/blob/main/cloudevents/spec.md#message
 	EncodingBinary Encoding = iota
-	// Structured encoding as specified in https://github.com/cloudevents/spec/blob/master/spec.md#message
+	// Structured encoding as specified in https://github.com/cloudevents/spec/blob/main/cloudevents/spec.md#message
 	EncodingStructured
 	// Message is an instance of EventMessage or it contains EventMessage nested (through MessageWrapper)
 	EncodingEvent
diff --git a/v2/event/eventcontext_v03.go b/v2/event/eventcontext_v03.go
index c511c81c4..3f0505547 100644
--- a/v2/event/eventcontext_v03.go
+++ b/v2/event/eventcontext_v03.go
@@ -179,7 +179,8 @@ func (ec EventContextV03) AsV1() *EventContextV1 {
 }
 
 // Validate returns errors based on requirements from the CloudEvents spec.
-// For more details, see https://github.com/cloudevents/spec/blob/master/spec.md
+// For more details, see
+// https://github.com/cloudevents/spec/blob/main/cloudevents/spec.md
 // As of Feb 26, 2019, commit 17c32ea26baf7714ad027d9917d03d2fff79fc7e
 // + https://github.com/cloudevents/spec/pull/387 -> datacontentencoding
 // + https://github.com/cloudevents/spec/pull/406 -> subject