diff --git a/blaze-markup.cabal b/blaze-markup.cabal
--- a/blaze-markup.cabal
+++ b/blaze-markup.cabal
@@ -1,5 +1,5 @@
 Name:         blaze-markup
-Version:      0.5.1.7
+Version:      0.5.2.0
 Homepage:     http://jaspervdj.be/blaze
 Bug-Reports:  http://github.com/jaspervdj/blaze-markup/issues
 License:      BSD3
diff --git a/src/Text/Blaze.hs b/src/Text/Blaze.hs
--- a/src/Text/Blaze.hs
+++ b/src/Text/Blaze.hs
@@ -66,6 +66,8 @@
     ) where
 
 import Data.Monoid (mconcat)
+import Data.Int (Int32, Int64)
+import Data.Word (Word, Word32, Word64)
 
 import Data.Text (Text)
 import qualified Data.Text.Lazy as LT
@@ -115,6 +117,14 @@
     toMarkup = string . show
     {-# INLINE toMarkup #-}
 
+instance ToMarkup Int32 where
+    toMarkup = string . show
+    {-# INLINE toMarkup #-}
+
+instance ToMarkup Int64 where
+    toMarkup = string . show
+    {-# INLINE toMarkup #-}
+
 instance ToMarkup Char where
     toMarkup = string . return
     {-# INLINE toMarkup #-}
@@ -135,6 +145,18 @@
     toMarkup = string . show
     {-# INLINE toMarkup #-}
 
+instance ToMarkup Word where
+    toMarkup = string . show
+    {-# INLINE toMarkup #-}
+
+instance ToMarkup Word32 where
+    toMarkup = string . show
+    {-# INLINE toMarkup #-}
+
+instance ToMarkup Word64 where
+    toMarkup = string . show
+    {-# INLINE toMarkup #-}
+
 -- | Class allowing us to use a single function for attribute values
 --
 class ToValue a where
@@ -174,6 +196,14 @@
     toValue = stringValue . show
     {-# INLINE toValue #-}
 
+instance ToValue Int32 where
+    toValue = stringValue . show
+    {-# INLINE toValue #-}
+
+instance ToValue Int64 where
+    toValue = stringValue . show
+    {-# INLINE toValue #-}
+
 instance ToValue Char where
     toValue = stringValue . return
     {-# INLINE toValue #-}
@@ -191,5 +221,17 @@
     {-# INLINE toValue #-}
 
 instance ToValue Double where
+    toValue = stringValue . show
+    {-# INLINE toValue #-}
+
+instance ToValue Word where
+    toValue = stringValue . show
+    {-# INLINE toValue #-}
+
+instance ToValue Word32 where
+    toValue = stringValue . show
+    {-# INLINE toValue #-}
+
+instance ToValue Word64 where
     toValue = stringValue . show
     {-# INLINE toValue #-}