diff --git a/CHANGELOG.md b/CHANGELOG.md
index a5fb54daa..5518d0425 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,7 @@ Change Log
 - Move focus to the editor when lines are selected by clicking line numbers.
 - Apply update of “Show invisible characters” option in the preferences immediately to opened documents.
 - Change the label of the option “Count each line ending as one character” in General pane to “Ignore line endings when counting characters” (the value reversed).
+- Disable “Hide Toolbar” command for the preferences window.
 - Improve general performance.
 
 
diff --git a/CotEditor/Base.lproj/PreferencesWindow.storyboard b/CotEditor/Base.lproj/PreferencesWindow.storyboard
index 3272f9a3b..8d56e460b 100644
--- a/CotEditor/Base.lproj/PreferencesWindow.storyboard
+++ b/CotEditor/Base.lproj/PreferencesWindow.storyboard
@@ -10,7 +10,7 @@
         <scene sceneID="oee-cm-yzv">
             <objects>
                 <windowController showSeguePresentationStyle="single" id="5CU-Ph-YiJ" sceneMemberID="viewController">
-                    <window key="window" title="Preferences" allowsToolTipsWhenApplicationIsInactive="NO" autorecalculatesKeyViewLoop="NO" releasedWhenClosed="NO" visibleAtLaunch="NO" frameAutosaveName="" animationBehavior="default" tabbingMode="disallowed" id="KjF-xP-N55" customClass="NSPanel">
+                    <window key="window" title="Preferences" allowsToolTipsWhenApplicationIsInactive="NO" autorecalculatesKeyViewLoop="NO" releasedWhenClosed="NO" visibleAtLaunch="NO" frameAutosaveName="" animationBehavior="default" tabbingMode="disallowed" id="KjF-xP-N55" customClass="PreferencesWindow" customModule="CotEditor" customModuleProvider="target">
                         <windowStyleMask key="styleMask" titled="YES" closable="YES"/>
                         <rect key="contentRect" x="425" y="461" width="560" height="320"/>
                         <rect key="screenRect" x="0.0" y="0.0" width="2560" height="1417"/>
diff --git a/CotEditor/CotEditor.xcodeproj/project.pbxproj b/CotEditor/CotEditor.xcodeproj/project.pbxproj
index e645c7d8a..2172a8ca0 100644
--- a/CotEditor/CotEditor.xcodeproj/project.pbxproj
+++ b/CotEditor/CotEditor.xcodeproj/project.pbxproj
@@ -442,6 +442,8 @@
 		2AA761361D45634400031AAF /* String+Counting.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2AA761341D45634400031AAF /* String+Counting.swift */; };
 		2AA7613A1D457BD500031AAF /* String+Indentation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2AA761391D457BD500031AAF /* String+Indentation.swift */; };
 		2AA7613B1D457BD500031AAF /* String+Indentation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2AA761391D457BD500031AAF /* String+Indentation.swift */; };
+		2AA79C7821CB7251005AD6AD /* PreferencesWindow.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2AA79C7721CB7251005AD6AD /* PreferencesWindow.swift */; };
+		2AA79C7921CB7251005AD6AD /* PreferencesWindow.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2AA79C7721CB7251005AD6AD /* PreferencesWindow.swift */; };
 		2AA7E97D1DBAAC950083B7ED /* Script.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2AA7E97C1DBAAC950083B7ED /* Script.swift */; };
 		2AA7E97E1DBAAC950083B7ED /* Script.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2AA7E97C1DBAAC950083B7ED /* Script.swift */; };
 		2AA86282212ED91400BB75C9 /* NSSplitViewController+Autosave.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2AA86281212ED91400BB75C9 /* NSSplitViewController+Autosave.swift */; };
@@ -1117,6 +1119,7 @@
 		2AA749C21D3C263300850802 /* DocumentWindowController.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = DocumentWindowController.swift; sourceTree = "<group>"; };
 		2AA761341D45634400031AAF /* String+Counting.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = "String+Counting.swift"; sourceTree = "<group>"; };
 		2AA761391D457BD500031AAF /* String+Indentation.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = "String+Indentation.swift"; sourceTree = "<group>"; };
+		2AA79C7721CB7251005AD6AD /* PreferencesWindow.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PreferencesWindow.swift; sourceTree = "<group>"; };
 		2AA7E97C1DBAAC950083B7ED /* Script.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Script.swift; sourceTree = "<group>"; };
 		2AA86281212ED91400BB75C9 /* NSSplitViewController+Autosave.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "NSSplitViewController+Autosave.swift"; sourceTree = "<group>"; };
 		2AAB4BF81D2435AC0049A68B /* DocumentInspectorViewController.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = DocumentInspectorViewController.swift; sourceTree = "<group>"; };
@@ -1582,6 +1585,7 @@
 			isa = PBXGroup;
 			children = (
 				2A44321B219AC1F8008A0A6B /* PreferencesTabViewController.swift */,
+				2AA79C7721CB7251005AD6AD /* PreferencesWindow.swift */,
 				2A149DC619018F9200A9D6EF /* Panes */,
 				2A2E03471A4BF808006ABE9F /* Syntax Edit Sheet */,
 				2A2E03481A4BF820006ABE9F /* Keybindings Edit Pane */,
@@ -2789,6 +2793,7 @@
 				2AA761361D45634400031AAF /* String+Counting.swift in Sources */,
 				2AA14CF91FA47E8900EAF586 /* ScriptDescriptor.swift in Sources */,
 				2A78BFAE1D1B138D00A583D2 /* EditPaneController.swift in Sources */,
+				2AA79C7921CB7251005AD6AD /* PreferencesWindow.swift in Sources */,
 				2A5D13301D1FACC900D38E6A /* FindPanelLayoutManager.swift in Sources */,
 				2A11F2141E669BFA005E1675 /* PointerBridge.swift in Sources */,
 				2AA45A4C1D2E871900A1A401 /* EditorViewController.swift in Sources */,
@@ -3198,6 +3203,7 @@
 				2AACB1CD1D195ABD0073775B /* ShortcutKeyField.swift in Sources */,
 				2A6FD9ED1D3A85D700A59784 /* String+NSRange.swift in Sources */,
 				2A733E8920BBB4AC0090D7CB /* String+Case.swift in Sources */,
+				2AA79C7821CB7251005AD6AD /* PreferencesWindow.swift in Sources */,
 				2ACFE58B1D20730B0005233A /* FindPanelContentViewController.swift in Sources */,
 				2A78BFA41D1B02ED00A583D2 /* WindowPaneController.swift in Sources */,
 				2AE73F40203D2FBB00D8903B /* NSLayoutManager+Range.swift in Sources */,
diff --git a/CotEditor/Sources/PreferencesWindow.swift b/CotEditor/Sources/PreferencesWindow.swift
new file mode 100644
index 000000000..feca4ff70
--- /dev/null
+++ b/CotEditor/Sources/PreferencesWindow.swift
@@ -0,0 +1,42 @@
+//
+//  PreferencesWindow.swift
+//
+//  CotEditor
+//  https://coteditor.com
+//
+//  Created by 1024jp on 2018-12-20.
+//
+//  ---------------------------------------------------------------------------
+//
+//  © 2018 1024jp
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//  https://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+//
+
+import Cocoa
+
+final class PreferencesWindow: NSPanel {
+    
+    /// disable "Hide Toolbar" menu item
+    override func validateMenuItem(_ menuItem: NSMenuItem) -> Bool {
+        
+        switch menuItem.action {
+        case #selector(toggleToolbarShown)?:
+            return false
+            
+        default:
+            return super.validateMenuItem(menuItem)
+        }
+    }
+    
+}