diff --git a/datamodel/high/base/security_requirement_test.go b/datamodel/high/base/security_requirement_test.go
new file mode 100644
index 0000000..e056255
--- /dev/null
+++ b/datamodel/high/base/security_requirement_test.go
@@ -0,0 +1,35 @@
+// Copyright 2022 Princess B33f Heavy Industries / Dave Shanley
+// SPDX-License-Identifier: MIT
+
+package base
+
+import (
+	lowmodel "github.com/pb33f/libopenapi/datamodel/low"
+	lowbase "github.com/pb33f/libopenapi/datamodel/low/base"
+	"github.com/stretchr/testify/assert"
+	"gopkg.in/yaml.v3"
+	"testing"
+)
+
+func TestNewSecurityRequirement(t *testing.T) {
+
+	var cNode yaml.Node
+
+	yml := `pizza:
+  - cheese
+  - tomato`
+
+	_ = yaml.Unmarshal([]byte(yml), &cNode)
+
+	var lowExt lowbase.SecurityRequirement
+	_ = lowmodel.BuildModel(cNode.Content[0], &lowExt)
+
+	_ = lowExt.Build(cNode.Content[0], nil)
+
+	highExt := NewSecurityRequirement(&lowExt)
+
+	assert.Len(t, highExt.Requirements["pizza"], 2)
+
+	wentLow := highExt.GoLow()
+	assert.Len(t, wentLow.Requirements.Value, 1)
+}
diff --git a/datamodel/high/v2/swagger_test.go b/datamodel/high/v2/swagger_test.go
index 6a3cab3..9d5c0df 100644
--- a/datamodel/high/v2/swagger_test.go
+++ b/datamodel/high/v2/swagger_test.go
@@ -182,10 +182,10 @@ func TestNewSwaggerDocument_Definitions_Responses(t *testing.T) {
 	assert.Len(t, x.Enum, 2)
 
 	wentQuiteLow := y.GoLow()
-	assert.Equal(t, 717, wentQuiteLow.Type.KeyNode.Line)
+	assert.Equal(t, 729, wentQuiteLow.Type.KeyNode.Line)
 
 	wentLowest := x.GoLow()
-	assert.Equal(t, 733, wentLowest.UniqueItems.KeyNode.Line)
+	assert.Equal(t, 745, wentLowest.UniqueItems.KeyNode.Line)
 }
 
 func TestNewSwaggerDocument_Definitions(t *testing.T) {
@@ -195,7 +195,7 @@ func TestNewSwaggerDocument_Definitions(t *testing.T) {
 	assert.Len(t, highDoc.Definitions.Definitions, 6)
 
 	wentLow := highDoc.Definitions.GoLow()
-	assert.Equal(t, 836, wentLow.FindSchema("User").ValueNode.Line)
+	assert.Equal(t, 848, wentLow.FindSchema("User").ValueNode.Line)
 
 }
 
diff --git a/datamodel/low/base/schema_proxy_test.go b/datamodel/low/base/schema_proxy_test.go
index 5df8126..4525a48 100644
--- a/datamodel/low/base/schema_proxy_test.go
+++ b/datamodel/low/base/schema_proxy_test.go
@@ -4,6 +4,7 @@
 package base
 
 import (
+	"github.com/pb33f/libopenapi/datamodel/low"
 	"github.com/stretchr/testify/assert"
 	"gopkg.in/yaml.v3"
 	"testing"
@@ -19,10 +20,19 @@ func TestSchemaProxy_Build(t *testing.T) {
 
 	err := sch.Build(idxNode.Content[0], nil)
 	assert.NoError(t, err)
+
+	assert.Equal(t, "3fc9b689459d738f8c88a3a48aa9e33542016b7a4052e001aaa536fca74813cb",
+		low.GenerateHashString(&sch))
+
 	assert.Equal(t, "something", sch.Schema().Description.Value)
 	assert.Empty(t, sch.GetSchemaReference())
 	assert.NotNil(t, sch.GetValueNode())
 	assert.False(t, sch.IsSchemaReference())
+
+	// already rendered, should spit out the same
+	assert.Equal(t, "3fc9b689459d738f8c88a3a48aa9e33542016b7a4052e001aaa536fca74813cb",
+		low.GenerateHashString(&sch))
+
 }
 
 func TestSchemaProxy_Build_CheckRef(t *testing.T) {
@@ -37,4 +47,6 @@ func TestSchemaProxy_Build_CheckRef(t *testing.T) {
 	assert.NoError(t, err)
 	assert.True(t, sch.IsSchemaReference())
 	assert.Equal(t, "wat", sch.GetSchemaReference())
+	assert.Equal(t, "f00a787f7492a95e165b470702f4fe9373583fbdc025b2c8bdf0262cc48fcff4",
+		low.GenerateHashString(&sch))
 }
diff --git a/datamodel/low/extraction_functions_test.go b/datamodel/low/extraction_functions_test.go
index 431f02d..1c0479e 100644
--- a/datamodel/low/extraction_functions_test.go
+++ b/datamodel/low/extraction_functions_test.go
@@ -4,6 +4,7 @@
 package low
 
 import (
+	"crypto/sha256"
 	"fmt"
 	"github.com/pb33f/libopenapi/index"
 	"github.com/pb33f/libopenapi/resolver"
@@ -1488,3 +1489,26 @@ x-tacos: [1,2,3]`
 		}
 	}
 }
+
+type test_fresh struct {
+	val string
+}
+
+func (f test_fresh) Hash() [32]byte {
+	return sha256.Sum256([]byte(f.val))
+}
+func TestAreEqual(t *testing.T) {
+	assert.True(t, AreEqual(test_fresh{val: "hello"}, test_fresh{val: "hello"}))
+	assert.False(t, AreEqual(test_fresh{val: "hello"}, test_fresh{val: "goodbye"}))
+	assert.False(t, AreEqual(nil, nil))
+}
+
+func TestGenerateHashString(t *testing.T) {
+
+	assert.Equal(t, "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824",
+		GenerateHashString(test_fresh{val: "hello"}))
+
+	assert.Equal(t, "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824",
+		GenerateHashString("hello"))
+
+}
diff --git a/datamodel/low/model_builder_test.go b/datamodel/low/model_builder_test.go
index 900793a..1989899 100644
--- a/datamodel/low/model_builder_test.go
+++ b/datamodel/low/model_builder_test.go
@@ -273,6 +273,51 @@ func TestSetField_ArrayHelper(t *testing.T) {
 	assert.Len(t, ins.Thing.Value, 3)
 }
 
+func TestSetField_Enum_Helper(t *testing.T) {
+
+	type internal struct {
+		Thing NodeReference[[]ValueReference[any]]
+	}
+
+	yml := `thing: 
+  - nice
+  - rice
+  - slice`
+
+	ins := new(internal)
+	var rootNode yaml.Node
+	mErr := yaml.Unmarshal([]byte(yml), &rootNode)
+	assert.NoError(t, mErr)
+
+	try := BuildModel(rootNode.Content[0], ins)
+	assert.NoError(t, try)
+	assert.Len(t, ins.Thing.Value, 3)
+}
+
+func TestSetField_Default_Helper(t *testing.T) {
+
+	type cake struct {
+		thing int
+	}
+
+	// this should be ignored, no custom objects in here my friend.
+	type internal struct {
+		Thing cake
+	}
+
+	yml := `thing: 
+  type: cake`
+
+	ins := new(internal)
+	var rootNode yaml.Node
+	mErr := yaml.Unmarshal([]byte(yml), &rootNode)
+	assert.NoError(t, mErr)
+
+	try := BuildModel(rootNode.Content[0], ins)
+	assert.NoError(t, try)
+	assert.Equal(t, 0, ins.Thing.thing)
+}
+
 func TestSetField_Ignore(t *testing.T) {
 
 	type Complex struct {
diff --git a/datamodel/low/reference.go b/datamodel/low/reference.go
index 85e17a9..e0d9c06 100644
--- a/datamodel/low/reference.go
+++ b/datamodel/low/reference.go
@@ -87,10 +87,12 @@ func (n NodeReference[T]) IsEmpty() bool {
 }
 
 func (n NodeReference[T]) IsReferenceNode() bool {
-	for k := range n.KeyNode.Content {
-		if k%2 == 0 {
-			if n.KeyNode.Content[k].Value == "$ref" {
-				return true
+	if n.KeyNode != nil {
+		for k := range n.KeyNode.Content {
+			if k%2 == 0 {
+				if n.KeyNode.Content[k].Value == "$ref" {
+					return true
+				}
 			}
 		}
 	}
diff --git a/datamodel/low/reference_test.go b/datamodel/low/reference_test.go
index 0c697e7..fd26971 100644
--- a/datamodel/low/reference_test.go
+++ b/datamodel/low/reference_test.go
@@ -4,6 +4,7 @@
 package low
 
 import (
+	"crypto/sha256"
 	"github.com/pb33f/libopenapi/index"
 	"github.com/pb33f/libopenapi/resolver"
 	"github.com/stretchr/testify/assert"
@@ -31,11 +32,28 @@ func TestNodeReference_Mutate(t *testing.T) {
 		Line:   22,
 		Column: 23,
 	}
+	nr.KeyNode = &yaml.Node{
+		Line:   22,
+		Column: 23,
+	}
 	n := nr.Mutate("nice one!")
+	assert.NotNil(t, nr.GetValueNode())
+	assert.Empty(t, nr.GetValue())
+	assert.False(t, nr.IsReferenceNode())
 	assert.Equal(t, "nice one!", n.Value)
 	assert.Equal(t, "nice one!", nr.ValueNode.Value)
 }
 
+func TestNodeReference_RefNode(t *testing.T) {
+	nr := new(NodeReference[string])
+	nr.KeyNode = &yaml.Node{
+		Content: []*yaml.Node{&yaml.Node{
+			Value: "$ref",
+		}},
+	}
+	assert.True(t, nr.IsReferenceNode())
+}
+
 func TestValueReference_Mutate(t *testing.T) {
 	nr := new(ValueReference[string])
 	nr.ValueNode = &yaml.Node{
@@ -59,6 +77,8 @@ func TestValueReference_GenerateMapKey(t *testing.T) {
 		Column: 23,
 	}
 	assert.Equal(t, "22:23", nr.GenerateMapKey())
+	assert.NotNil(t, nr.GetValueNode())
+	assert.Empty(t, nr.GetValue())
 }
 
 func TestKeyReference_IsEmpty(t *testing.T) {
@@ -307,5 +327,10 @@ func TestGetCircularReferenceResult_NothingFound(t *testing.T) {
 	_ = yaml.Unmarshal([]byte(yml), &idxNode)
 
 	assert.Nil(t, GetCircularReferenceResult(idxNode.Content[0], idx))
+}
+
+func TestHashToString(t *testing.T) {
+	assert.Equal(t, "5994471abb01112afcc18159f6cc74b4f511b99806da59b3caf5a9c173cacfc5",
+		HashToString(sha256.Sum256([]byte("12345"))))
 
 }
diff --git a/datamodel/low/v2/definitions_test.go b/datamodel/low/v2/definitions_test.go
index 5d35893..2195e8b 100644
--- a/datamodel/low/v2/definitions_test.go
+++ b/datamodel/low/v2/definitions_test.go
@@ -49,6 +49,26 @@ func TestDefinitions_Parameters_Build_Error(t *testing.T) {
 
 }
 
+func TestDefinitions_Hash(t *testing.T) {
+
+	yml := `nice:
+  description: rice`
+
+	var idxNode yaml.Node
+	mErr := yaml.Unmarshal([]byte(yml), &idxNode)
+	assert.NoError(t, mErr)
+	idx := index.NewSpecIndex(&idxNode)
+
+	var n Definitions
+	err := low.BuildModel(&idxNode, &n)
+	assert.NoError(t, err)
+
+	_ = n.Build(idxNode.Content[0], idx)
+	assert.Equal(t, "26d23786e6873e1a337f8e9be85f7de1490e4ff6cd303c3b15e593a25a6a149d",
+		low.GenerateHashString(&n))
+
+}
+
 func TestDefinitions_Responses_Build_Error(t *testing.T) {
 
 	yml := `gonna:
diff --git a/datamodel/low/v3/components.go b/datamodel/low/v3/components.go
index 9f7fd55..3175b8f 100644
--- a/datamodel/low/v3/components.go
+++ b/datamodel/low/v3/components.go
@@ -166,14 +166,14 @@ func extractComponentValues[T low.Buildable[N], N any](label string, root *yaml.
 	// for every component, build in a new thread!
 	bChan := make(chan componentBuildResult[T])
 	eChan := make(chan error)
-	var buildComponent = func(label *yaml.Node, value *yaml.Node, c chan componentBuildResult[T], ec chan<- error) {
+	var buildComponent = func(parentLabel string, label *yaml.Node, value *yaml.Node, c chan componentBuildResult[T], ec chan<- error) {
 		var n T = new(N)
 
 		// if this is a reference, extract it (although components with references is an antipattern)
 		// If you're building components as references... pls... stop, this code should not need to be here.
 		// TODO: check circular crazy on this. It may explode
 		var err error
-		if h, _, _ := utils.IsNodeRefValue(value); h && label.Value != SchemasLabel {
+		if h, _, _ := utils.IsNodeRefValue(value); h && parentLabel != SchemasLabel {
 			value, err = low.LocateRefNode(value, idx)
 		}
 		if err != nil {
@@ -210,7 +210,7 @@ func extractComponentValues[T low.Buildable[N], N any](label string, root *yaml.
 			continue
 		}
 		totalComponents++
-		go buildComponent(currentLabel, v, bChan, eChan)
+		go buildComponent(label, currentLabel, v, bChan, eChan)
 	}
 
 	completedComponents := 0
diff --git a/datamodel/low/v3/components_test.go b/datamodel/low/v3/components_test.go
index e385337..deb363f 100644
--- a/datamodel/low/v3/components_test.go
+++ b/datamodel/low/v3/components_test.go
@@ -138,6 +138,28 @@ func TestComponents_Build_Fail(t *testing.T) {
 
 }
 
+func TestComponents_Build_ParameterFail(t *testing.T) {
+
+	yml := `components:
+  parameters:
+    pizza:
+      schema:
+        $ref: '#/this is a problem.'`
+
+	var idxNode yaml.Node
+	mErr := yaml.Unmarshal([]byte(yml), &idxNode)
+	assert.NoError(t, mErr)
+	idx := index.NewSpecIndex(&idxNode)
+
+	var n Components
+	err := low.BuildModel(&idxNode, &n)
+	assert.NoError(t, err)
+
+	err = n.Build(idxNode.Content[0], idx)
+	assert.Error(t, err)
+
+}
+
 func TestComponents_Build_Fail_TypeFail(t *testing.T) {
 
 	yml := `components:
diff --git a/datamodel/spec_info_test.go b/datamodel/spec_info_test.go
index 7836341..75647a5 100644
--- a/datamodel/spec_info_test.go
+++ b/datamodel/spec_info_test.go
@@ -53,6 +53,12 @@ info:
 servers:
   - url: https://quobix.com/api`
 
+var OpenApi31 = `openapi: 3.1
+info:
+  title: Test API, valid, but not quite valid 
+servers:
+  - url: https://quobix.com/api`
+
 var OpenApiFalse = `openapi: false
 info:
   title: Test API version is a bool?
@@ -161,6 +167,14 @@ func TestExtractSpecInfo_OpenAPIWat(t *testing.T) {
 	assert.Equal(t, "3.2", r.Version)
 }
 
+func TestExtractSpecInfo_OpenAPI31(t *testing.T) {
+
+	r, e := ExtractSpecInfo([]byte(OpenApi31))
+	assert.Nil(t, e)
+	assert.Equal(t, OpenApi3, r.SpecType)
+	assert.Equal(t, "3.1", r.Version)
+}
+
 func TestExtractSpecInfo_OpenAPIFalse(t *testing.T) {
 
 	spec, e := ExtractSpecInfo([]byte(OpenApiFalse))
diff --git a/test_specs/petstorev2-complete.yaml b/test_specs/petstorev2-complete.yaml
index c017f04..fce75ea 100644
--- a/test_specs/petstorev2-complete.yaml
+++ b/test_specs/petstorev2-complete.yaml
@@ -714,6 +714,18 @@ responses:
       $ref: '#/definitions/ApiResponse'
     headers:
       someHeader:
+        format: something
+        pattern: a nice pattern
+        exclusiveMinimum: false
+        exclusiveMaximum: false
+        minimum: 1
+        maximum: 2
+        maxItems: 3
+        minItems: 1
+        minLength: 1
+        maxLength: 10
+        multipleOf: 20
+        uniqueItems: false
         type: array
         enum: [one, two]
         items:
diff --git a/utils/utils.go b/utils/utils.go
index c6fe555..40c8f9e 100644
--- a/utils/utils.go
+++ b/utils/utils.go
@@ -274,22 +274,6 @@ func FindKeyNodeFullTop(key string, nodes []*yaml.Node) (keyNode *yaml.Node, lab
 			return nodes[i], nodes[i], nodes[i+1] // next node is what we need.
 		}
 	}
-	for q, v := range nodes {
-		if q%2 != 0 {
-			continue
-		}
-		if key == v.Value {
-			if IsNodeMap(v) {
-				if q+1 == len(v.Content) {
-					return v, v.Content[q], v.Content[q]
-				}
-				return v, v.Content[q], v.Content[q+1]
-			}
-			if IsNodeArray(v) {
-				return v, v.Content[q], v.Content[q]
-			}
-		}
-	}
 	return nil, nil, nil
 }
 
diff --git a/utils/utils_test.go b/utils/utils_test.go
index 03f869c..5024a6e 100644
--- a/utils/utils_test.go
+++ b/utils/utils_test.go
@@ -424,6 +424,34 @@ func TestFindKeyNode_NotFound(t *testing.T) {
 	assert.Nil(t, v)
 }
 
+func TestFindKeyFullNodeTop(t *testing.T) {
+	a := &yaml.Node{
+		Value: "fish",
+	}
+	b := &yaml.Node{
+		Value: "paste",
+	}
+
+	c, d, e := FindKeyNodeFullTop("fish", []*yaml.Node{a, b})
+	assert.Equal(t, "fish", c.Value)
+	assert.Equal(t, "fish", d.Value)
+	assert.Equal(t, "paste", e.Value)
+}
+
+func TestFindKeyFullNode_NotFound(t *testing.T) {
+	a := &yaml.Node{
+		Value: "fish",
+	}
+	b := &yaml.Node{
+		Value: "paste",
+	}
+
+	c, d, e := FindKeyNodeFullTop("lemons", []*yaml.Node{a, b})
+	assert.Nil(t, c)
+	assert.Nil(t, d)
+	assert.Nil(t, e)
+}
+
 func TestMakeTagReadable(t *testing.T) {
 	n := &yaml.Node{
 		Tag: "!!map",
@@ -599,6 +627,8 @@ func TestDetectCase(t *testing.T) {
 	assert.Equal(t, SnakeCase, DetectCase("snakes_on_a_plane"))
 	assert.Equal(t, KebabCase, DetectCase("chicken-be-be-beef-or-pork"))
 	assert.Equal(t, RegularCase, DetectCase("kebab-TimeIn_london-TOWN"))
+	assert.Equal(t, UnknownCase, DetectCase(""))
+
 }
 
 func TestIsNodeRefValue(t *testing.T) {
diff --git a/what-changed/model/comparison_functions.go b/what-changed/model/comparison_functions.go
index 529525f..f1dd086 100644
--- a/what-changed/model/comparison_functions.go
+++ b/what-changed/model/comparison_functions.go
@@ -175,9 +175,10 @@ func CheckForModification[T any](l, r *yaml.Node, label string, changes *[]*Chan
 		CreateChange(changes, Modified, label, l, r, breaking, orig, new)
 	}
 	// the values may have not changed, but the tag (node type) type may have
-	if l != nil && l.Value != "" && r != nil && r.Value != "" && r.Value != l.Value && r.Tag != l.Tag {
-		CreateChange(changes, Modified, label, l, r, breaking, orig, new)
-	}
+	// todo: this is currently untestable, no a single test triggers it (yet)
+	//if l != nil && l.Value != "" && r != nil && r.Value != "" && r.Value != l.Value && r.Tag != l.Tag {
+	//	CreateChange(changes, Modified, label, l, r, breaking, orig, new)
+	//}
 }
 
 // CheckMapForChanges checks a left and right low level map for any additions, subtractions or modifications to
@@ -227,6 +228,7 @@ func CheckMapForChanges[T any, R any](expLeft, expRight map[low.KeyReference[str
 		chLock.Lock()
 		expChanges[k] = compareFunc(p[k].Value, h[k].Value)
 		chLock.Unlock()
+
 		doneChan <- true
 	}
 
@@ -256,75 +258,6 @@ func CheckMapForChanges[T any, R any](expLeft, expRight map[low.KeyReference[str
 	return expChanges
 }
 
-//// CheckMapForChangesUntyped checks a left and right low level map for any additions, subtractions or modifications to
-//// values. The compareFunc  can be generic and accept any type
-//func CheckMapForChangesUntyped[T any, R any](expLeft, expRight map[low.KeyReference[string]]low.ValueReference[T],
-//	changes *[]*Change, label string, compareFunc func(l, r any) R) map[string]R {
-//
-//	lHashes := make(map[string]string)
-//	rHashes := make(map[string]string)
-//	lValues := make(map[string]low.ValueReference[T])
-//	rValues := make(map[string]low.ValueReference[T])
-//
-//	for k := range expLeft {
-//		lHashes[k.Value] = low.GenerateHashString(expLeft[k].Value)
-//		lValues[k.Value] = expLeft[k]
-//	}
-//
-//	for k := range expRight {
-//		rHashes[k.Value] = low.GenerateHashString(expRight[k].Value)
-//		rValues[k.Value] = expRight[k]
-//	}
-//
-//	expChanges := make(map[string]R)
-//
-//	checkLeft := func(k string, doneChan chan bool, f, g map[string]string, p, h map[string]low.ValueReference[T]) {
-//		rhash := g[k]
-//		if rhash == "" {
-//			if p[k].GetValueNode().Value == "" {
-//				p[k].GetValueNode().Value = k // yes, a dirty thing, but it's clean for the consumer.
-//			}
-//			CreateChange(changes, ObjectRemoved, label,
-//				p[k].GetValueNode(), nil, true,
-//				p[k].GetValue(), nil)
-//			doneChan <- true
-//			return
-//		}
-//		if f[k] == g[k] {
-//			doneChan <- true
-//			return
-//		}
-//		// run comparison.
-//		expChanges[k] = compareFunc(p[k].Value, h[k].Value)
-//		doneChan <- true
-//	}
-//
-//	doneChan := make(chan bool)
-//	count := 0
-//
-//	// check left example hashes
-//	for k := range lHashes {
-//		count++
-//		go checkLeft(k, doneChan, lHashes, rHashes, lValues, rValues)
-//	}
-//
-//	//check right example hashes
-//	for k := range rHashes {
-//		count++
-//		go checkRightValue(k, doneChan, lHashes, rValues, changes, label)
-//	}
-//
-//	// wait for all done signals.
-//	completed := 0
-//	for completed < count {
-//		select {
-//		case <-doneChan:
-//			completed++
-//		}
-//	}
-//	return expChanges
-//}
-
 func checkRightValue[T any](k string, doneChan chan bool, f map[string]string, p map[string]low.ValueReference[T],
 	changes *[]*Change, label string, lock *sync.Mutex) {
 
diff --git a/what-changed/model/components_test.go b/what-changed/model/components_test.go
index 55a0b5a..703a411 100644
--- a/what-changed/model/components_test.go
+++ b/what-changed/model/components_test.go
@@ -8,6 +8,7 @@ import (
 	"github.com/pb33f/libopenapi/datamodel/low/v2"
 	"github.com/pb33f/libopenapi/datamodel/low/v3"
 	"github.com/pb33f/libopenapi/index"
+	"github.com/pb33f/libopenapi/resolver"
 	"github.com/stretchr/testify/assert"
 	"gopkg.in/yaml.v3"
 	"testing"
@@ -770,6 +771,50 @@ func TestCompareComponents_OpenAPI_Responses_FullBuild_IdenticalRef(t *testing.T
 	assert.Nil(t, extChanges)
 }
 
+func TestCompareComponents_OpenAPI_Responses_FullBuild_CircularRef(t *testing.T) {
+	left := `components:
+  responses:
+    coffee:
+      $ref: '#/components/responses/tv'
+    tv:
+      $ref: '#/components/responses/coffee'`
+
+	right := `components:
+  responses:
+    coffee:
+      $ref: '#/components/responses/tv'
+    tv:
+      $ref: '#/components/responses/coffee'`
+
+	var lNode, rNode yaml.Node
+	_ = yaml.Unmarshal([]byte(left), &lNode)
+	_ = yaml.Unmarshal([]byte(right), &rNode)
+
+	// create low level objects
+	var lDoc v3.Components
+	var rDoc v3.Components
+
+	_ = low.BuildModel(lNode.Content[0], &lDoc)
+	_ = low.BuildModel(rNode.Content[0], &rDoc)
+
+	idx := index.NewSpecIndex(&lNode)
+	idx2 := index.NewSpecIndex(&rNode)
+
+	// resolver required to check circular refs.
+	re1 := resolver.NewResolver(idx)
+	re2 := resolver.NewResolver(idx2)
+
+	re1.CheckForCircularReferences()
+	re2.CheckForCircularReferences()
+
+	_ = lDoc.Build(lNode.Content[0], idx)
+	_ = rDoc.Build(rNode.Content[0], idx2)
+
+	// compare.
+	extChanges := CompareComponents(&lDoc, &rDoc)
+	assert.Nil(t, extChanges)
+}
+
 func TestCompareComponents_OpenAPI_Responses_Modify(t *testing.T) {
 
 	left := `responses:
@@ -1205,6 +1250,38 @@ func TestCompareComponents_OpenAPI_SecuritySchemes_Equal(t *testing.T) {
 	assert.Nil(t, extChanges)
 }
 
+func TestCompareComponents_OpenAPI_SecuritySchemes_Modified(t *testing.T) {
+
+	left := `securitySchemes:
+  scheme1:
+    description: a scheme
+  scheme2:
+    description: another scheme`
+
+	right := `securitySchemes:
+  scheme1:
+    description: a scheme that changed
+  scheme2:
+    description: another scheme that also changed`
+
+	var lNode, rNode yaml.Node
+	_ = yaml.Unmarshal([]byte(left), &lNode)
+	_ = yaml.Unmarshal([]byte(right), &rNode)
+
+	// create low level objects
+	var lDoc v3.Components
+	var rDoc v3.Components
+	_ = low.BuildModel(lNode.Content[0], &lDoc)
+	_ = low.BuildModel(rNode.Content[0], &rDoc)
+	_ = lDoc.Build(lNode.Content[0], nil)
+	_ = rDoc.Build(rNode.Content[0], nil)
+
+	// compare.
+	extChanges := CompareComponents(&lDoc, &rDoc)
+	assert.Equal(t, 2, extChanges.TotalChanges())
+	assert.Equal(t, 0, extChanges.TotalBreakingChanges())
+}
+
 func TestCompareComponents_OpenAPI_Links_Equal(t *testing.T) {
 
 	left := `links:
diff --git a/what-changed/model/schema_test.go b/what-changed/model/schema_test.go
index 03be331..81c7926 100644
--- a/what-changed/model/schema_test.go
+++ b/what-changed/model/schema_test.go
@@ -225,7 +225,7 @@ func TestCompareSchemas_RefChanged(t *testing.T) {
 	assert.NotNil(t, changes)
 	assert.Len(t, changes.Changes, 1)
 	assert.Equal(t, Modified, changes.Changes[0].ChangeType)
-	assert.Equal(t, "string", changes.Changes[0].New)
+	assert.Equal(t, "#/components/schemas/Yo", changes.Changes[0].New)
 }
 
 func TestCompareSchemas_RefToInline(t *testing.T) {
@@ -253,8 +253,8 @@ func TestCompareSchemas_RefToInline(t *testing.T) {
 	assert.NotNil(t, changes)
 	assert.Len(t, changes.Changes, 1)
 	assert.Equal(t, Modified, changes.Changes[0].ChangeType)
-	assert.Equal(t, v3.TypeLabel, changes.Changes[0].Property)
-	assert.Equal(t, "int", changes.Changes[0].Original)
+	assert.Equal(t, v3.RefLabel, changes.Changes[0].Property)
+	assert.Equal(t, "#/components/schemas/Yo", changes.Changes[0].Original)
 
 }
 
@@ -283,8 +283,8 @@ func TestCompareSchemas_InlineToRef(t *testing.T) {
 	assert.NotNil(t, changes)
 	assert.Len(t, changes.Changes, 1)
 	assert.Equal(t, Modified, changes.Changes[0].ChangeType)
-	assert.Equal(t, v3.TypeLabel, changes.Changes[0].Property)
-	assert.Equal(t, "int", changes.Changes[0].New)
+	assert.Equal(t, v3.RefLabel, changes.Changes[0].Property)
+	assert.Equal(t, "#/components/schemas/Yo", changes.Changes[0].New)
 
 }
 
@@ -313,6 +313,31 @@ func TestCompareSchemas_Identical(t *testing.T) {
 	assert.Nil(t, changes)
 }
 
+func TestCompareSchemas_Identical_Ref(t *testing.T) {
+	left := `components:
+  schemas:
+    Yo:
+      type: int
+    OK:
+      $ref: '#/components/schemas/Yo'`
+
+	right := `components:
+  schemas:
+    Yo:
+      type: int
+    OK:
+       $ref: '#/components/schemas/Yo'`
+
+	leftDoc, rightDoc := test_BuildDoc(left, right)
+
+	// extract left reference schema and non reference schema.
+	lSchemaProxy := leftDoc.Components.Value.FindSchema("OK").Value
+	rSchemaProxy := rightDoc.Components.Value.FindSchema("OK").Value
+
+	changes := CompareSchemas(rSchemaProxy, lSchemaProxy)
+	assert.Nil(t, changes)
+}
+
 func TestCompareSchemas_RequiredAdded(t *testing.T) {
 	left := `components:
   schemas: