diff --git a/Makefile b/Makefile
index ff8d1621..6b3bd29c 100644
--- a/Makefile
+++ b/Makefile
@@ -49,7 +49,7 @@ samples: build
 	@protoc --plugin=bin/protoc-gen-jsonschema --jsonschema_out=jsonschemas --proto_path=${PROTO_PATH} ${PROTO_PATH}/Proto2Required.proto || echo "No messages found (Proto2Required.proto)"
 	@protoc --plugin=bin/protoc-gen-jsonschema --jsonschema_out=jsonschemas --proto_path=${PROTO_PATH} ${PROTO_PATH}/Proto2NestedMessage.proto || echo "No messages found (Proto2NestedMessage.proto)"
 	@protoc --plugin=bin/protoc-gen-jsonschema --jsonschema_out=jsonschemas --proto_path=${PROTO_PATH} ${PROTO_PATH}/GoogleValue.proto || echo "No messages found (GoogleValue.proto)"
-	@protoc --plugin=bin/protoc-gen-jsonschema --jsonschema_out=jsonschemas -I. --proto_path=${PROTO_PATH} ${PROTO_PATH}/OptionFileExtention.proto || echo "No messages found (OptionFileExtention.proto)"
+	@protoc --plugin=bin/protoc-gen-jsonschema --jsonschema_out=jsonschemas -I. --proto_path=${PROTO_PATH} ${PROTO_PATH}/OptionFileExtension.proto || echo "No messages found (OptionFileExtension.proto)"
 	@protoc --plugin=bin/protoc-gen-jsonschema --jsonschema_out=jsonschemas -I. --proto_path=${PROTO_PATH} ${PROTO_PATH}/OptionIgnoredField.proto || echo "No messages found (HiddenFields.proto)"
 	@protoc --plugin=bin/protoc-gen-jsonschema --jsonschema_out=jsonschemas -I. --proto_path=${PROTO_PATH} ${PROTO_PATH}/OptionIgnoredFile.proto || echo "No messages found (IgnoredFile.proto)"
 	@protoc --plugin=bin/protoc-gen-jsonschema --jsonschema_out=jsonschemas -I. --proto_path=${PROTO_PATH} ${PROTO_PATH}/OptionIgnoredMessage.proto || echo "No messages found (IgnoredMessage.proto)"
diff --git a/README.md b/README.md
index b3561714..ed1c16e5 100644
--- a/README.md
+++ b/README.md
@@ -79,7 +79,7 @@ The following configuration parameters are supported. They should be added to th
 |`disallow_additional_properties`| Disallow additional properties in schema |
 |`disallow_bigints_as_strings`| Disallow big integers as strings |
 |`enforce_oneof`| Interpret Proto "oneOf" clauses |
-|`file_extention`| Specify a custom file extention for generated schemas |
+|`file_extension`| Specify a custom file extension for generated schemas |
 |`json_fieldnames`| Use JSON field names only |
 |`prefix_schema_files_with_package`| Prefix the output filename with package |
 |`proto_and_json_fieldnames`| Use proto and JSON field names |
@@ -102,7 +102,7 @@ These apply to specifically marked fields, giving you more finely-grained contro
 These options apply to an entire proto file.
 
 - [ignore](internal/converter/testdata/proto/OptionIgnoredFile.proto): Ignore (skip) a specific file
-- [extention](internal/converter/testdata/proto/OptionFileExtention.proto): Specify a custom file-extention for the generated schema for this file
+- [extension](internal/converter/testdata/proto/OptionFileExtension.proto): Specify a custom file-extension for the generated schema for this file
 
 ### Message Options
 
@@ -192,13 +192,13 @@ protoc \
 --proto_path=testdata/proto testdata/proto/ArrayOfPrimitives.proto
 ```
 
-### Custom schema file extention
+### Custom schema file extension
 
-The default file extention is `json`. You can override that with the "file_extention" parameter.
+The default file extension is `json`. You can override that with the "file_extension" parameter.
 
 ```sh
 protoc \
---jsonschema_out=file_extention=jsonschema:. \
+--jsonschema_out=file_extension=jsonschema:. \
 --proto_path=internal/converter/testdata/proto internal/converter/testdata/proto/ArrayOfPrimitives.proto
 ```
 
diff --git a/internal/converter/converter.go b/internal/converter/converter.go
index 305bcbe3..ecfdaa72 100644
--- a/internal/converter/converter.go
+++ b/internal/converter/converter.go
@@ -18,7 +18,7 @@ import (
 )
 
 const (
-	defaultFileExtention = "json"
+	defaultFileExtension = "json"
 	defaultRefPrefix     = "#/definitions/"
 	messageDelimiter     = "+"
 )
@@ -30,7 +30,7 @@ type Converter struct {
 	logger              *logrus.Logger
 	refPrefix           string
 	requiredFieldOption string
-	schemaFileExtention string
+	schemaFileExtension string
 	sourceInfo          *sourceCodeInfo
 	messageTargets      []string
 }
@@ -52,7 +52,7 @@ func New(logger *logrus.Logger) *Converter {
 	return &Converter{
 		logger:              logger,
 		refPrefix:           defaultRefPrefix,
-		schemaFileExtention: defaultFileExtention,
+		schemaFileExtension: defaultFileExtension,
 	}
 }
 
@@ -109,9 +109,9 @@ func (c *Converter) parseGeneratorParameters(parameters string) {
 			c.messageTargets = strings.Split(matches[1], messageDelimiter)
 		}
 
-		// Configure custom file extention:
-		if parameterParts := strings.Split(parameter, "file_extention="); len(parameterParts) == 2 {
-			c.schemaFileExtention = parameterParts[1]
+		// Configure custom file extension:
+		if parameterParts := strings.Split(parameter, "file_extension="); len(parameterParts) == 2 {
+			c.schemaFileExtension = parameterParts[1]
 		}
 	}
 }
@@ -143,7 +143,7 @@ func (c *Converter) convertEnumType(enum *descriptor.EnumDescriptorProto) (jsons
 }
 
 // Converts a proto file into a JSON-Schema:
-func (c *Converter) convertFile(file *descriptor.FileDescriptorProto, fileExtention string) ([]*plugin.CodeGeneratorResponse_File, error) {
+func (c *Converter) convertFile(file *descriptor.FileDescriptorProto, fileExtension string) ([]*plugin.CodeGeneratorResponse_File, error) {
 
 	// Input filename:
 	protoFileName := path.Base(file.GetName())
@@ -166,7 +166,7 @@ func (c *Converter) convertFile(file *descriptor.FileDescriptorProto, fileExtent
 	// Generate standalone ENUMs:
 	if len(file.GetMessageType()) == 0 {
 		for _, enum := range file.GetEnumType() {
-			jsonSchemaFileName := c.generateSchemaFilename(file, fileExtention, enum.GetName())
+			jsonSchemaFileName := c.generateSchemaFilename(file, fileExtension, enum.GetName())
 			c.logger.WithField("proto_filename", protoFileName).WithField("enum_name", enum.GetName()).WithField("jsonschema_filename", jsonSchemaFileName).Info("Generating JSON-schema for stand-alone ENUM")
 
 			// Convert the ENUM:
@@ -227,7 +227,7 @@ func (c *Converter) convertFile(file *descriptor.FileDescriptorProto, fileExtent
 			}
 
 			// Generate a schema filename:
-			jsonSchemaFileName := c.generateSchemaFilename(file, fileExtention, msgDesc.GetName())
+			jsonSchemaFileName := c.generateSchemaFilename(file, fileExtension, msgDesc.GetName())
 			c.logger.WithField("proto_filename", protoFileName).WithField("msg_name", msgDesc.GetName()).WithField("jsonschema_filename", jsonSchemaFileName).Info("Generating JSON-schema for MESSAGE")
 
 			// Marshal the JSON-Schema into JSON:
@@ -268,8 +268,8 @@ func (c *Converter) convert(request *plugin.CodeGeneratorRequest) (*plugin.CodeG
 	// Go through the list of proto files provided by protoc:
 	for _, fileDesc := range request.GetProtoFile() {
 
-		// Start with the default / global file extention:
-		fileExtention := c.schemaFileExtention
+		// Start with the default / global file extension:
+		fileExtension := c.schemaFileExtension
 
 		// Check for our custom field options:
 		if opts := fileDesc.GetOptions(); opts != nil && proto.HasExtension(opts, protos.E_FileOptions) {
@@ -282,10 +282,10 @@ func (c *Converter) convert(request *plugin.CodeGeneratorRequest) (*plugin.CodeG
 						continue
 					}
 
-					// Allow the file extention option to take precedence:
-					if fileOptions.GetExtention() != "" {
-						fileExtention = fileOptions.GetExtention()
-						c.logger.WithField("file_name", fileDesc.GetName()).WithField("extention", fileExtention).Debug("Using optional extention")
+					// Allow the file extension option to take precedence:
+					if fileOptions.GetExtension() != "" {
+						fileExtension = fileOptions.GetExtension()
+						c.logger.WithField("file_name", fileDesc.GetName()).WithField("extension", fileExtension).Debug("Using optional extension")
 					}
 				}
 			}
@@ -312,7 +312,7 @@ func (c *Converter) convert(request *plugin.CodeGeneratorRequest) (*plugin.CodeG
 		// Generate schemas for this file:
 		if _, ok := generateTargets[fileDesc.GetName()]; ok {
 			c.logger.WithField("filename", fileDesc.GetName()).Debug("Converting file")
-			converted, err := c.convertFile(fileDesc, fileExtention)
+			converted, err := c.convertFile(fileDesc, fileExtension)
 			if err != nil {
 				response.Error = proto.String(fmt.Sprintf("Failed to convert %s: %v", fileDesc.GetName(), err))
 				return response, err
@@ -323,11 +323,11 @@ func (c *Converter) convert(request *plugin.CodeGeneratorRequest) (*plugin.CodeG
 	return response, nil
 }
 
-func (c *Converter) generateSchemaFilename(file *descriptor.FileDescriptorProto, fileExtention, protoName string) string {
+func (c *Converter) generateSchemaFilename(file *descriptor.FileDescriptorProto, fileExtension, protoName string) string {
 	if c.Flags.PrefixSchemaFilesWithPackage {
-		return fmt.Sprintf("%s/%s.%s", file.GetPackage(), protoName, fileExtention)
+		return fmt.Sprintf("%s/%s.%s", file.GetPackage(), protoName, fileExtension)
 	}
-	return fmt.Sprintf("%s.%s", protoName, fileExtention)
+	return fmt.Sprintf("%s.%s", protoName, fileExtension)
 }
 
 func contains(haystack []string, needle string) bool {
diff --git a/internal/converter/converter_test.go b/internal/converter/converter_test.go
index 3d714a11..23433eca 100644
--- a/internal/converter/converter_test.go
+++ b/internal/converter/converter_test.go
@@ -286,11 +286,11 @@ func configureSampleProtos() map[string]sampleProto {
 			ObjectsToValidateFail: []string{testdata.OptionDisallowAdditionalPropertiesFail},
 			ObjectsToValidatePass: []string{testdata.OptionDisallowAdditionalPropertiesPass},
 		},
-		"OptionFileExtention": {
-			ExpectedJSONSchema: []string{testdata.OptionFileExtention},
-			ExpectedFileNames:  []string{"OptionFileExtention.jsonschema"},
-			FilesToGenerate:    []string{"OptionFileExtention.proto"},
-			ProtoFileName:      "OptionFileExtention.proto",
+		"OptionFileExtension": {
+			ExpectedJSONSchema: []string{testdata.OptionFileExtension},
+			ExpectedFileNames:  []string{"OptionFileExtension.jsonschema"},
+			FilesToGenerate:    []string{"OptionFileExtension.proto"},
+			ProtoFileName:      "OptionFileExtension.proto",
 		},
 		"OptionIgnoredFile": {
 			ExpectedJSONSchema: []string{},
diff --git a/internal/converter/testdata/file_options.go b/internal/converter/testdata/file_options.go
index 51531b24..47de4448 100644
--- a/internal/converter/testdata/file_options.go
+++ b/internal/converter/testdata/file_options.go
@@ -10,9 +10,9 @@ const FileOptions = `{
                     "type": "boolean",
                     "description": "Files tagged with this will not be processed"
                 },
-                "extention": {
+                "extension": {
                     "type": "string",
-                    "description": "Override the default file extention for schemas generated from this file"
+                    "description": "Override the default file extension for schemas generated from this file"
                 }
             },
             "additionalProperties": true,
diff --git a/internal/converter/testdata/option_file_extention.go b/internal/converter/testdata/option_file_extension.go
similarity index 85%
rename from internal/converter/testdata/option_file_extention.go
rename to internal/converter/testdata/option_file_extension.go
index 3aafbe4a..e842104d 100644
--- a/internal/converter/testdata/option_file_extention.go
+++ b/internal/converter/testdata/option_file_extension.go
@@ -1,10 +1,10 @@
 package testdata
 
-const OptionFileExtention = `{
+const OptionFileExtension = `{
     "$schema": "http://json-schema.org/draft-04/schema#",
-    "$ref": "#/definitions/OptionFileExtention",
+    "$ref": "#/definitions/OptionFileExtension",
     "definitions": {
-        "OptionFileExtention": {
+        "OptionFileExtension": {
             "properties": {
                 "name2": {
                     "type": "string"
diff --git a/internal/converter/testdata/proto/OptionFileExtention.proto b/internal/converter/testdata/proto/OptionFileExtension.proto
similarity index 69%
rename from internal/converter/testdata/proto/OptionFileExtention.proto
rename to internal/converter/testdata/proto/OptionFileExtension.proto
index 50c669e6..9ed9bc62 100644
--- a/internal/converter/testdata/proto/OptionFileExtention.proto
+++ b/internal/converter/testdata/proto/OptionFileExtension.proto
@@ -2,9 +2,9 @@ syntax = "proto3";
 package samples;
 import "options.proto";
 
-option (protoc.gen.jsonschema.file_options).extention = "jsonschema";
+option (protoc.gen.jsonschema.file_options).extension = "jsonschema";
 
-message OptionFileExtention {
+message OptionFileExtension {
     string name2       = 1;
     string timestamp2  = 2;
     int32 id2          = 3;
diff --git a/internal/protos/options.pb.go b/internal/protos/options.pb.go
index b1f2b31d..d8afbb13 100644
--- a/internal/protos/options.pb.go
+++ b/internal/protos/options.pb.go
@@ -91,8 +91,8 @@ type FileOptions struct {
 
 	// Files tagged with this will not be processed
 	Ignore bool `protobuf:"varint,1,opt,name=ignore,proto3" json:"ignore,omitempty"`
-	// Override the default file extention for schemas generated from this file
-	Extention string `protobuf:"bytes,2,opt,name=extention,proto3" json:"extention,omitempty"`
+	// Override the default file extension for schemas generated from this file
+	Extension string `protobuf:"bytes,2,opt,name=extension,proto3" json:"extension,omitempty"`
 }
 
 func (x *FileOptions) Reset() {
@@ -134,9 +134,9 @@ func (x *FileOptions) GetIgnore() bool {
 	return false
 }
 
-func (x *FileOptions) GetExtention() string {
+func (x *FileOptions) GetExtension() string {
 	if x != nil {
-		return x.Extention
+		return x.Extension
 	}
 	return ""
 }
@@ -276,8 +276,8 @@ var file_options_proto_rawDesc = []byte{
 	0x28, 0x08, 0x52, 0x08, 0x72, 0x65, 0x71, 0x75, 0x69, 0x72, 0x65, 0x64, 0x22, 0x43, 0x0a, 0x0b,
 	0x46, 0x69, 0x6c, 0x65, 0x4f, 0x70, 0x74, 0x69, 0x6f, 0x6e, 0x73, 0x12, 0x16, 0x0a, 0x06, 0x69,
 	0x67, 0x6e, 0x6f, 0x72, 0x65, 0x18, 0x01, 0x20, 0x01, 0x28, 0x08, 0x52, 0x06, 0x69, 0x67, 0x6e,
-	0x6f, 0x72, 0x65, 0x12, 0x1c, 0x0a, 0x09, 0x65, 0x78, 0x74, 0x65, 0x6e, 0x74, 0x69, 0x6f, 0x6e,
-	0x18, 0x02, 0x20, 0x01, 0x28, 0x09, 0x52, 0x09, 0x65, 0x78, 0x74, 0x65, 0x6e, 0x74, 0x69, 0x6f,
+	0x6f, 0x72, 0x65, 0x12, 0x1c, 0x0a, 0x09, 0x65, 0x78, 0x74, 0x65, 0x6e, 0x73, 0x69, 0x6f, 0x6e,
+	0x18, 0x02, 0x20, 0x01, 0x28, 0x09, 0x52, 0x09, 0x65, 0x78, 0x74, 0x65, 0x6e, 0x73, 0x69, 0x6f,
 	0x6e, 0x22, 0xca, 0x01, 0x0a, 0x0e, 0x4d, 0x65, 0x73, 0x73, 0x61, 0x67, 0x65, 0x4f, 0x70, 0x74,
 	0x69, 0x6f, 0x6e, 0x73, 0x12, 0x16, 0x0a, 0x06, 0x69, 0x67, 0x6e, 0x6f, 0x72, 0x65, 0x18, 0x01,
 	0x20, 0x01, 0x28, 0x08, 0x52, 0x06, 0x69, 0x67, 0x6e, 0x6f, 0x72, 0x65, 0x12, 0x2e, 0x0a, 0x13,
diff --git a/jsonschemas/FileOptions.json b/jsonschemas/FileOptions.json
index 418505f7..f2239299 100644
--- a/jsonschemas/FileOptions.json
+++ b/jsonschemas/FileOptions.json
@@ -8,9 +8,9 @@
                     "type": "boolean",
                     "description": "Files tagged with this will not be processed"
                 },
-                "extention": {
+                "extension": {
                     "type": "string",
-                    "description": "Override the default file extention for schemas generated from this file"
+                    "description": "Override the default file extension for schemas generated from this file"
                 }
             },
             "additionalProperties": true,
diff --git a/jsonschemas/OptionFileExtention.jsonschema b/jsonschemas/OptionFileExtension.jsonschema
similarity index 88%
rename from jsonschemas/OptionFileExtention.jsonschema
rename to jsonschemas/OptionFileExtension.jsonschema
index a092d483..08ee918b 100644
--- a/jsonschemas/OptionFileExtention.jsonschema
+++ b/jsonschemas/OptionFileExtension.jsonschema
@@ -1,8 +1,8 @@
 {
     "$schema": "http://json-schema.org/draft-04/schema#",
-    "$ref": "#/definitions/OptionFileExtention",
+    "$ref": "#/definitions/OptionFileExtension",
     "definitions": {
-        "OptionFileExtention": {
+        "OptionFileExtension": {
             "properties": {
                 "name2": {
                     "type": "string"
diff --git a/options.proto b/options.proto
index 1a1b3d46..835aaec6 100644
--- a/options.proto
+++ b/options.proto
@@ -25,8 +25,8 @@ message FileOptions {
   // Files tagged with this will not be processed
   bool ignore = 1;
 
-  // Override the default file extention for schemas generated from this file
-  string extention = 2;
+  // Override the default file extension for schemas generated from this file
+  string extension = 2;
 }