diff --git a/share/qtcreator/themes/dark.creatortheme b/share/qtcreator/themes/dark.creatortheme
index e0e02c6d49d..357fdf2b263 100644
--- a/share/qtcreator/themes/dark.creatortheme
+++ b/share/qtcreator/themes/dark.creatortheme
@@ -1,6 +1,6 @@
 [General]
 ThemeName=Dark
-PreferredStyles=Fusion
+PreferredStyles=
 DefaultTextEditorColorScheme=dark.xml
 
 [Palette]
diff --git a/share/qtcreator/themes/design-light.creatortheme b/share/qtcreator/themes/design-light.creatortheme
index 9f5dae6d574..197070dc9bc 100644
--- a/share/qtcreator/themes/design-light.creatortheme
+++ b/share/qtcreator/themes/design-light.creatortheme
@@ -1,6 +1,6 @@
 [General]
 ThemeName=Design Light
-PreferredStyles=Fusion
+PreferredStyles=
 
 
 [Palette]
diff --git a/share/qtcreator/themes/design.creatortheme b/share/qtcreator/themes/design.creatortheme
index 8fe6d59b5d8..3e4af0791ab 100644
--- a/share/qtcreator/themes/design.creatortheme
+++ b/share/qtcreator/themes/design.creatortheme
@@ -1,6 +1,6 @@
 [General]
 ThemeName=Design Dark
-PreferredStyles=Fusion
+PreferredStyles=
 DefaultTextEditorColorScheme=creator-dark.xml
 
 [Palette]
diff --git a/share/qtcreator/themes/flat-dark.creatortheme b/share/qtcreator/themes/flat-dark.creatortheme
index a09df062adb..26d1827bc88 100644
--- a/share/qtcreator/themes/flat-dark.creatortheme
+++ b/share/qtcreator/themes/flat-dark.creatortheme
@@ -1,6 +1,6 @@
 [General]
 ThemeName=Flat Dark
-PreferredStyles=Fusion
+PreferredStyles=
 DefaultTextEditorColorScheme=creator-dark.xml
 
 [Palette]
diff --git a/src/libs/utils/theme/theme.cpp b/src/libs/utils/theme/theme.cpp
index 463f01e43de..a1154b52617 100644
--- a/src/libs/utils/theme/theme.cpp
+++ b/src/libs/utils/theme/theme.cpp
@@ -67,13 +67,14 @@ void setThemeApplicationPalette()
         QApplication::setPalette(m_creatorTheme->palette());
 }
 
-static void maybeForceMacOSLight(Theme *theme)
+static void setMacAppearance(Theme *theme)
 {
 #ifdef Q_OS_MACOS
     // Match the native UI theme and palette with the creator
-    // theme by forcing light aqua for light creator themes.
-    if (theme && !theme->flag(Theme::DarkUserInterface))
-        Internal::forceMacOSLightAquaApperance();
+    // theme by forcing light aqua for light creator themes
+    // and dark aqua for dark themes.
+    if (theme)
+        Internal::forceMacAppearance(theme->flag(Theme::DarkUserInterface));
 #else
     Q_UNUSED(theme)
 #endif
@@ -96,7 +97,7 @@ void setCreatorTheme(Theme *theme)
     delete m_creatorTheme;
     m_creatorTheme = theme;
 
-    maybeForceMacOSLight(theme);
+    setMacAppearance(theme);
     setThemeApplicationPalette();
 }
 
@@ -120,6 +121,10 @@ Theme::~Theme()
 
 QStringList Theme::preferredStyles() const
 {
+    // Force Fusion style if we have a dark theme on Windows or Linux,
+    // because the default QStyle might not be up for it
+    if (!HostOsInfo::isMacHost() && d->preferredStyles.isEmpty() && flag(DarkUserInterface))
+        return {"Fusion"};
     return d->preferredStyles;
 }
 
@@ -291,7 +296,7 @@ static QPalette copyPalette(const QPalette &p)
 void Theme::setInitialPalette(Theme *initTheme)
 {
     macOSSystemIsDark(); // initialize value for system mode
-    maybeForceMacOSLight(initTheme);
+    setMacAppearance(initTheme);
     initialPalette();
 }
 
diff --git a/src/libs/utils/theme/theme_mac.h b/src/libs/utils/theme/theme_mac.h
index 8c48e52734c..eb920ca12ef 100644
--- a/src/libs/utils/theme/theme_mac.h
+++ b/src/libs/utils/theme/theme_mac.h
@@ -28,7 +28,7 @@
 namespace Utils {
 namespace Internal {
 
-void forceMacOSLightAquaApperance();
+void forceMacAppearance(bool dark);
 bool currentAppearanceIsDark();
 
 } // Internal
diff --git a/src/libs/utils/theme/theme_mac.mm b/src/libs/utils/theme/theme_mac.mm
index d1d623e3a80..b6898f49bbb 100644
--- a/src/libs/utils/theme/theme_mac.mm
+++ b/src/libs/utils/theme/theme_mac.mm
@@ -39,26 +39,36 @@
 namespace Utils {
 namespace Internal {
 
-void forceMacOSLightAquaApperance()
-{
-#if __has_builtin(__builtin_available)
-    if (__builtin_available(macOS 10.14, *))
-#else // Xcode 8
-    if (QOperatingSystemVersion::current() >= QOperatingSystemVersion(QOperatingSystemVersion::MacOS, 10, 14, 0))
-#endif
-        NSApp.appearance = [NSAppearance appearanceNamed:NSAppearanceNameAqua];
-}
-
-bool currentAppearanceIsDark()
+bool currentAppearanceMatches(bool dark)
 {
 #if __has_builtin(__builtin_available)
     if (__builtin_available(macOS 10.14, *)) {
         auto appearance = [NSApp.effectiveAppearance
             bestMatchFromAppearancesWithNames:@[NSAppearanceNameAqua, NSAppearanceNameDarkAqua]];
-        return [appearance isEqualToString:NSAppearanceNameDarkAqua];
+        return
+            [appearance isEqualToString:(dark ? NSAppearanceNameDarkAqua : NSAppearanceNameAqua)];
     }
 #endif
-    return false;
+    return true;
+}
+
+void forceMacAppearance(bool dark)
+{
+    if (currentAppearanceMatches(dark))
+        return;
+#if __has_builtin(__builtin_available)
+    if (__builtin_available(macOS 10.14, *))
+#else // Xcode 8
+    if (QOperatingSystemVersion::current() >= QOperatingSystemVersion(QOperatingSystemVersion::MacOS, 10, 14, 0))
+#endif
+        NSApp.appearance = [NSAppearance
+            appearanceNamed:(dark ? NSAppearanceNameDarkAqua : NSAppearanceNameAqua)];
+}
+
+bool currentAppearanceIsDark()
+{
+    // double negation, so we get "false" for macOS 10.13
+    return !currentAppearanceMatches(false /*==light*/);
 }
 
 } // Internal