diff --git a/.github/workflows/go.yml b/.github/workflows/go.yml
index f8f3669fc..41b196f7d 100644
--- a/.github/workflows/go.yml
+++ b/.github/workflows/go.yml
@@ -25,14 +25,18 @@ jobs:
         go-version: 1.x
     - run: go version
 
-    - run: go mod download && go mod verify
-    - run: go test ./...
+    - run: go mod download && go mod tidy && go mod verify
+    - run: git --no-pager diff && [[ $(git --no-pager diff --name-only | wc -l) = 0 ]]
+      shell: bash
+
     - run: go vet ./...
+    - run: git --no-pager diff && [[ $(git --no-pager diff --name-only | wc -l) = 0 ]]
+      shell: bash
+
     - run: go fmt ./...
     - run: git --no-pager diff && [[ $(git --no-pager diff --name-only | wc -l) = 0 ]]
       shell: bash
+
     - run: go test ./...
     - run: git --no-pager diff && [[ $(git --no-pager diff --name-only | wc -l) = 0 ]]
       shell: bash
-    - run: go get -u -a -v ./... && go mod tidy && go mod verify
-    - run: git --no-pager diff
diff --git a/go.sum b/go.sum
index 60f84360b..f1e462c68 100644
--- a/go.sum
+++ b/go.sum
@@ -1,4 +1,3 @@
-github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -8,8 +7,10 @@ github.com/go-openapi/jsonpointer v0.19.5 h1:gZr+CIYByUqjcgeLXnQu2gHYQC9o73G2XUe
 github.com/go-openapi/jsonpointer v0.19.5/go.mod h1:Pl9vOtqEWErmShwVjC8pYs9cog34VGT37dQOVbmoatg=
 github.com/go-openapi/swag v0.19.5 h1:lTz6Ys4CmqqCQmZPBlbQENR1/GucA2bzYTE12Pw4tFY=
 github.com/go-openapi/swag v0.19.5/go.mod h1:POnQmlKehdgb5mhVOsnJFsivZCEZ/vjK9gh66Z9tfKk=
+github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/mailru/easyjson v0.0.0-20190614124828-94de47d64c63/go.mod h1:C1wdFJiN94OJF2b5HbByQZoLdCWB1Yqtg26g4irojpc=
 github.com/mailru/easyjson v0.0.0-20190626092158-b2ccc519800e h1:hB2xlXdHp/pmPZq0y3QnmWAArdw9PqbmotexnWx/FU8=
@@ -20,8 +21,8 @@ github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.5.1 h1:nOGnQDM7FYENwehXlg/kFVnos3rEvtKTjRvOWSzb6H4=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.3.0 h1:clyUAQHOM3G0M3f5vQj7LuJrETvjVot3Z5el9nffUtU=
diff --git a/openapi2conv/openapi2_conv.go b/openapi2conv/openapi2_conv.go
index 03a880279..f3f8c5c34 100644
--- a/openapi2conv/openapi2_conv.go
+++ b/openapi2conv/openapi2_conv.go
@@ -782,9 +782,9 @@ func FromV3SecurityRequirements(requirements openapi3.SecurityRequirements) open
 	if requirements == nil {
 		return nil
 	}
-	result := make([]map[string][]string, len(requirements))
-	for i, item := range requirements {
-		result[i] = item
+	result := make([]map[string][]string, 0, len(requirements))
+	for _, item := range requirements {
+		result = append(result, item)
 	}
 	return result
 }
diff --git a/openapi3/swagger_loader.go b/openapi3/swagger_loader.go
index ed2b05225..6755b2917 100644
--- a/openapi3/swagger_loader.go
+++ b/openapi3/swagger_loader.go
@@ -37,14 +37,14 @@ type SwaggerLoader struct {
 	visitedFiles    map[string]struct{}
 	visitedSwaggers map[string]*Swagger
 
+	visitedExample        map[*Example]struct{}
 	visitedHeader         map[*Header]struct{}
+	visitedLink           map[*Link]struct{}
 	visitedParameter      map[*Parameter]struct{}
 	visitedRequestBody    map[*RequestBody]struct{}
 	visitedResponse       map[*Response]struct{}
 	visitedSchema         map[*Schema]struct{}
 	visitedSecurityScheme map[*SecurityScheme]struct{}
-	visitedExample        map[*Example]struct{}
-	visitedLink           map[*Link]struct{}
 }
 
 // NewSwaggerLoader returns an empty SwaggerLoader
@@ -192,15 +192,29 @@ func (swaggerLoader *SwaggerLoader) loadSwaggerFromDataWithPathInternal(data []b
 
 // ResolveRefsIn expands references if for instance spec was just unmarshalled
 func (swaggerLoader *SwaggerLoader) ResolveRefsIn(swagger *Swagger, path *url.URL) (err error) {
+	if swaggerLoader.visitedExample == nil {
+		swaggerLoader.visitedExample = make(map[*Example]struct{})
+	}
 	if swaggerLoader.visitedHeader == nil {
 		swaggerLoader.visitedHeader = make(map[*Header]struct{})
+	}
+	if swaggerLoader.visitedLink == nil {
+		swaggerLoader.visitedLink = make(map[*Link]struct{})
+	}
+	if swaggerLoader.visitedParameter == nil {
 		swaggerLoader.visitedParameter = make(map[*Parameter]struct{})
+	}
+	if swaggerLoader.visitedRequestBody == nil {
 		swaggerLoader.visitedRequestBody = make(map[*RequestBody]struct{})
+	}
+	if swaggerLoader.visitedResponse == nil {
 		swaggerLoader.visitedResponse = make(map[*Response]struct{})
+	}
+	if swaggerLoader.visitedSchema == nil {
 		swaggerLoader.visitedSchema = make(map[*Schema]struct{})
+	}
+	if swaggerLoader.visitedSecurityScheme == nil {
 		swaggerLoader.visitedSecurityScheme = make(map[*SecurityScheme]struct{})
-		swaggerLoader.visitedExample = make(map[*Example]struct{})
-		swaggerLoader.visitedLink = make(map[*Link]struct{})
 	}
 	if swaggerLoader.visitedFiles == nil {
 		swaggerLoader.reset()