diff --git a/History.md b/History.md
index 7c83160..727e548 100644
--- a/History.md
+++ b/History.md
@@ -1,7 +1,13 @@
+4.0.4 / 2020-09-01
+==================
+
+ * fix: should not quote directives like LocalForward (#38)
+
+
 4.0.3 / 2020-08-24
 ==================
 
- * fix: quote values that contain white spaces
+ * fix: quote values that contain white spaces (36)
 
 
 4.0.2 / 2020-02-09
diff --git a/index.js b/index.js
index 54bdddc..906b084 100644
--- a/index.js
+++ b/index.js
@@ -6,6 +6,7 @@ const RE_SPACE = /\s/
 const RE_LINE_BREAK = /\r|\n/
 const RE_SECTION_DIRECTIVE = /^(Host|Match)$/i
 const RE_MULTI_VALUE_DIRECTIVE = /^(GlobalKnownHostsFile|Host|IPQoS|SendEnv|UserKnownHostsFile)$/i
+const RE_QUOTE_DIRECTIVE = /^(?:CertificateFile|IdentifyFile|User)$/i
 
 const DIRECTIVE = 1
 const COMMENT = 2
@@ -172,7 +173,7 @@ class SSHConfig extends Array {
       }
       else if (line.type === DIRECTIVE) {
         const quoted = line.quoted
-          || (!/Command$/i.test(line.param) && RE_SPACE.test(line.value))
+          || (RE_QUOTE_DIRECTIVE.test(line.param) && RE_SPACE.test(line.value))
         const value = formatValue(line.value, quoted)
         str += `${line.param}${line.separator}${value}`
       }
diff --git a/package.json b/package.json
index c91d7d6..cec5c69 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "ssh-config",
   "description": "SSH config parser and stringifier",
-  "version": "4.0.3",
+  "version": "4.0.4",
   "author": "Chen Yangjian (https://www.cyj.me)",
   "repository": {
     "type": "git",
diff --git a/test/test.stringify.js b/test/test.stringify.js
index b7999d3..a0453c9 100644
--- a/test/test.stringify.js
+++ b/test/test.stringify.js
@@ -80,4 +80,17 @@ describe('stringify', function() {
         User "dan abramov"
     */}))
   })
+
+  // #38
+  it('.stringify LocalForward without quotes', function() {
+    const config = parse(heredoc(function() {/*
+      Host example
+        LocalForward 1234 localhost:1234
+    */}))
+
+    assert.equal(stringify(config), heredoc(function() {/*
+      Host example
+        LocalForward 1234 localhost:1234
+    */}))
+  })
 })