diff --git a/echo.go b/echo.go
index d45144d8c..a0b3070e1 100644
--- a/echo.go
+++ b/echo.go
@@ -64,6 +64,7 @@ import (
 type (
 	// Echo is the top-level framework instance.
 	Echo struct {
+		common
 		StdLogger        *stdLog.Logger
 		colorer          *color.Color
 		premiddleware    []MiddlewareFunc
@@ -125,10 +126,8 @@ type (
 	// Map defines a generic map of type `map[string]interface{}`.
 	Map map[string]interface{}
 
-	// i is the interface for Echo and Group.
-	i interface {
-		GET(string, HandlerFunc, ...MiddlewareFunc) *Route
-	}
+	// Common struct for Echo & Group.
+	common struct{}
 )
 
 // HTTP methods
@@ -225,7 +224,7 @@ const (
 
 const (
 	// Version of Echo
-	Version = "4.1.2"
+	Version = "4.1.3"
 	website = "https://echo.labstack.com"
 	// http://patorjk.com/software/taag/#p=display&f=Small%20Slant&t=Echo
 	banner = `
@@ -461,10 +460,10 @@ func (e *Echo) Static(prefix, root string) *Route {
 	if root == "" {
 		root = "." // For security we want to restrict to CWD.
 	}
-	return static(e, prefix, root)
+	return e.static(prefix, root, e.GET)
 }
 
-func static(i i, prefix, root string) *Route {
+func (_ common) static(prefix, root string, get func(string, HandlerFunc, ...MiddlewareFunc) *Route) *Route {
 	h := func(c Context) error {
 		p, err := url.PathUnescape(c.Param("*"))
 		if err != nil {
@@ -473,21 +472,26 @@ func static(i i, prefix, root string) *Route {
 		name := filepath.Join(root, path.Clean("/"+p)) // "/"+ for security
 		return c.File(name)
 	}
-	i.GET(prefix, h)
+	get(prefix, h)
 	if prefix == "/" {
-		return i.GET(prefix+"*", h)
+		return get(prefix+"*", h)
 	}
 
-	return i.GET(prefix+"/*", h)
+	return get(prefix+"/*", h)
 }
 
-// File registers a new route with path to serve a static file with optional route-level middleware.
-func (e *Echo) File(path, file string, m ...MiddlewareFunc) *Route {
-	return e.GET(path, func(c Context) error {
+func (_ common) file(path, file string, get func(string, HandlerFunc, ...MiddlewareFunc) *Route,
+	m ...MiddlewareFunc) *Route {
+	return get(path, func(c Context) error {
 		return c.File(file)
 	}, m...)
 }
 
+// File registers a new route with path to serve a static file with optional route-level middleware.
+func (e *Echo) File(path, file string, m ...MiddlewareFunc) *Route {
+	return e.file(path, file, e.GET, m...)
+}
+
 func (e *Echo) add(host, method, path string, handler HandlerFunc, middleware ...MiddlewareFunc) *Route {
 	name := handlerName(handler)
 	router := e.findRouter(host)
diff --git a/group.go b/group.go
index a14667e82..e674cad4f 100644
--- a/group.go
+++ b/group.go
@@ -10,6 +10,7 @@ type (
 	// routes that share a common middleware or functionality that should be separate
 	// from the parent echo instance while still inheriting from it.
 	Group struct {
+		common
 		host       string
 		prefix     string
 		middleware []MiddlewareFunc
@@ -23,7 +24,7 @@ func (g *Group) Use(middleware ...MiddlewareFunc) {
 	// Allow all requests to reach the group as they might get dropped if router
 	// doesn't find a match, making none of the group middleware process.
 	for _, p := range []string{"", "/*"} {
-		g.echo.Any(path.Clean(g.prefix+p), func(c Context) error {
+		g.Any(path.Clean(g.prefix+p), func(c Context) error {
 			return NotFoundHandler(c)
 		}, g.middleware...)
 	}
@@ -104,12 +105,12 @@ func (g *Group) Group(prefix string, middleware ...MiddlewareFunc) (sg *Group) {
 
 // Static implements `Echo#Static()` for sub-routes within the Group.
 func (g *Group) Static(prefix, root string) {
-	static(g, prefix, root)
+	g.static(prefix, root, g.GET)
 }
 
 // File implements `Echo#File()` for sub-routes within the Group.
 func (g *Group) File(path, file string) {
-	g.echo.File(g.prefix+path, file)
+	g.file(g.prefix+path, file, g.GET)
 }
 
 // Add implements `Echo#Add()` for sub-routes within the Group.
diff --git a/middleware/logger.go b/middleware/logger.go
index 83b52b26a..6fd59efbc 100644
--- a/middleware/logger.go
+++ b/middleware/logger.go
@@ -2,6 +2,7 @@ package middleware
 
 import (
 	"bytes"
+	"encoding/json"
 	"io"
 	"os"
 	"strconv"
@@ -175,7 +176,10 @@ func LoggerWithConfig(config LoggerConfig) echo.MiddlewareFunc {
 					return buf.WriteString(s)
 				case "error":
 					if err != nil {
-						return buf.WriteString(err.Error())
+						// Error may contain invalid JSON e.g. `"`
+						b, _ := json.Marshal(err.Error())
+						b = b[1 : len(b)-1]
+						return buf.Write(b)
 					}
 				case "latency":
 					l := stop.Sub(start)