diff --git a/.golangci.yml b/.golangci.yml
index f7f80eef..2a6ee813 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -43,7 +43,7 @@ linters:
     - contextcheck
     - cyclop
     - decorder
-    - depguard
+    # depguard
     - dogsled
     - dupl
     - durationcheck
@@ -81,6 +81,7 @@ linters:
     - goprintffuncname
     - gosec
     - gosimple
+    - gosmopolitan
     - govet
     - grouper
     - importas
@@ -91,6 +92,7 @@ linters:
     - loggercheck
     - maintidx
     - makezero
+    - mirror
     - misspell
     - musttag
     - nakedret
@@ -112,6 +114,7 @@ linters:
     - sqlclosecheck
     - staticcheck
     - stylecheck
+    - tagalign
     - tagliatelle
     - tenv
     - testableexamples
@@ -128,6 +131,7 @@ linters:
     - whitespace
     - wrapcheck
     # wsl
+    - zerologlint
 
 issues:
   exclude-rules:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9b5b4aa4..6feb987b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,7 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 ## [v0.2.0] - 3/18/2023
 
 ### Removed
+
 - Remove file.WithLog to favor standard log.Printf (#32).
 
 ## [v0.1.0] - 3/12/2023
diff --git a/README.md b/README.md
index b5f0daa1..834f84e8 100644
--- a/README.md
+++ b/README.md
@@ -108,4 +108,3 @@ compatibility with these versions in the following manner:
   testing for the oldest (now archived upstream) version of Go. This, and
   future, releases of konf may include features only supported by
   the currently supported versions of Go.
-
diff --git a/global.go b/global.go
index 18cc29d3..36faf18b 100644
--- a/global.go
+++ b/global.go
@@ -64,7 +64,7 @@ func Watch(ctx context.Context, fns ...func()) error {
 }
 
 // SetGlobal makes c the global Config. After this call,
-// the konf package's functions (e.g. konf.Get) will read from config.
+// the konf package's functions (e.g. konf.Get) will read from the global config.
 //
 // The default global config only loads configuration from environment variables.
 func SetGlobal(config *Config) {
diff --git a/internal/maps/merge.go b/internal/maps/merge.go
index e4de2823..3556df23 100644
--- a/internal/maps/merge.go
+++ b/internal/maps/merge.go
@@ -14,9 +14,9 @@ func Merge(dst, src map[string]any) {
 		// Ensure key is lower case since the path is case-insensitive.
 		key = strings.ToLower(key)
 
-		// Add the srcVal if the key does not exist in the dst map.
-		dstVal, exist := dst[key]
-		if !exist {
+		// Direct override if the dstVal is not map[string]any.
+		dstMap, succeed := dst[key].(map[string]any)
+		if !succeed {
 			dst[key] = srcVal
 
 			continue
@@ -30,14 +30,6 @@ func Merge(dst, src map[string]any) {
 			continue
 		}
 
-		// Direct override if the dstVal is not map[string]any.
-		dstMap, succeed := dstVal.(map[string]any)
-		if !succeed {
-			dst[key] = srcVal
-
-			continue
-		}
-
 		// Merge if the srcVal and dstVal are both map[string]any.
 		Merge(dstMap, srcMap)
 	}
diff --git a/provider.go b/provider.go
index e07df064..b2ae034d 100644
--- a/provider.go
+++ b/provider.go
@@ -9,8 +9,7 @@ import "context"
 //
 // Load loads configuration and returns as a nested map[string]any.
 // It requires that the string keys should be nested like `{parent: {child: {key: 1}}}`.
-// The key in returned map should be case-insensitive,
-// otherwise random overridden exists.
+// The key in returned map should be case-insensitive, otherwise random overridden exists.
 type Loader interface {
 	Load() (map[string]any, error)
 }
@@ -26,10 +25,8 @@ type Watcher interface {
 
 // ConfigAware is the interface that wraps the WithConfig method.
 //
-// WithConfig enables provider loads configuration from providers
-// before it in Load and Watch methods.
-//
-// It ensures the WithConfig is called before Load and Watch.
+// WithConfig enables provider loads configuration from providers before it.
+// It ensures the WithConfig is called before executing methods in Loader and Watcher.
 type ConfigAware interface {
 	WithConfig(*Config)
 }
diff --git a/provider/pflag/pflag.go b/provider/pflag/pflag.go
index 5ac1e8c2..bb1b614f 100644
--- a/provider/pflag/pflag.go
+++ b/provider/pflag/pflag.go
@@ -47,19 +47,21 @@ func New(opts ...Option) PFlag {
 
 func (f PFlag) Load() (map[string]any, error) {
 	values := make(map[string]any)
-	f.set.VisitAll(func(flag *pflag.Flag) {
-		if f.prefix != "" && !strings.HasPrefix(flag.Name, f.prefix) {
-			return
-		}
+	f.set.VisitAll(
+		func(flag *pflag.Flag) {
+			if f.prefix != "" && !strings.HasPrefix(flag.Name, f.prefix) {
+				return
+			}
 
-		val := f.flagVal(flag)
-		// Skip zero default value to avoid overriding values set by other loader.
-		if !flag.Changed && reflect.ValueOf(val).IsZero() {
-			return
-		}
+			val := f.flagVal(flag)
+			// Skip zero default value to avoid overriding values set by other loader.
+			if !flag.Changed && reflect.ValueOf(val).IsZero() {
+				return
+			}
 
-		maps.Insert(values, strings.Split(flag.Name, f.delimiter), val)
-	})
+			maps.Insert(values, strings.Split(flag.Name, f.delimiter), val)
+		},
+	)
 
 	return values, nil
 }