diff --git a/app/Commands/Html/Options.hs b/app/Commands/Html/Options.hs
index 0dd06ba2bf..b7e395696d 100644
--- a/app/Commands/Html/Options.hs
+++ b/app/Commands/Html/Options.hs
@@ -37,7 +37,7 @@ parseHtml = do
           <> metavar "THEME"
           <> value Ayu
           <> showDefault
-          <> help "Theme for syntax highlighting. Options: ayu (light) and nord (dark)"
+          <> help ("Theme for syntax highlighting. " <> availableStr)
           <> completeWith (map show allThemes)
       )
   _htmlOutputDir <-
@@ -77,8 +77,22 @@ parseHtml = do
     allThemes :: [Theme]
     allThemes = allElements
 
+    availableStr :: String
+    availableStr =
+      dotSep
+        [ showCategory (light, filter ((== light) . themeLight) allThemes)
+          | light <- allElements
+        ]
+      where
+        showCategory :: (ThemeLight, [Theme]) -> String
+        showCategory (light, ts) = show light <> " themes: " <> commaSep (map show ts)
+        commaSep = intercalate ", "
+        dotSep = intercalate ". "
+
     parseTheme :: String -> Either String Theme
-    parseTheme s = case map toLower s of
-      "nord" -> Right Nord
-      "ayu" -> Right Ayu
-      _ -> Left $ "unrecognised theme: " <> s
+    parseTheme s = case lookup (map toLower s) themes of
+      Just t -> return t
+      Nothing -> Left $ "unrecognised theme: " <> s
+      where
+        themes :: [(String, Theme)]
+        themes = [(show theme, theme) | theme <- allThemes]
diff --git a/src/Juvix/Compiler/Backend/Html/Data/Options.hs b/src/Juvix/Compiler/Backend/Html/Data/Options.hs
index f61b13d03a..26dd9d652f 100644
--- a/src/Juvix/Compiler/Backend/Html/Data/Options.hs
+++ b/src/Juvix/Compiler/Backend/Html/Data/Options.hs
@@ -1,6 +1,7 @@
 module Juvix.Compiler.Backend.Html.Data.Options where
 
 import Juvix.Prelude
+import Prelude (show)
 
 data HtmlOptions = HtmlOptions
   { _htmlOptionsKind :: HtmlKind,
@@ -15,7 +16,22 @@ data HtmlOptions = HtmlOptions
 data Theme
   = Nord
   | Ayu
-  deriving stock (Show, Enum, Bounded, Data)
+  deriving stock (Enum, Eq, Ord, Bounded, Data)
+
+instance Show Theme where
+  show = \case
+    Nord -> "nord"
+    Ayu -> "ayu"
+
+data ThemeLight
+  = Dark
+  | Light
+  deriving stock (Show, Eq, Enum, Ord, Bounded, Data)
+
+themeLight :: Theme -> ThemeLight
+themeLight = \case
+  Nord -> Dark
+  Ayu -> Light
 
 data HtmlKind
   = HtmlDoc
diff --git a/tests/smoke/Commands/html.smoke.yaml b/tests/smoke/Commands/html.smoke.yaml
index bb10af059b..60b50831e2 100644
--- a/tests/smoke/Commands/html.smoke.yaml
+++ b/tests/smoke/Commands/html.smoke.yaml
@@ -1,6 +1,19 @@
 working-directory: ./../../../examples/
 
 tests:
+  - name: html-help-theme
+    command:
+        - juvix
+        - html
+        - --help
+    stdout:
+      matches:
+        regex: |
+          .*Theme for syntax highlighting. Dark themes: .*Light themes.*
+        options:
+          - dot-all
+    exit-status: 0
+
   - name: html-stdout
     command:
       shell: