diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,11 @@
 
 See full history at: <https://github.com/faylang/fay/commits>
 
-#### 0.23.1.0
+### 0.23.1.1
+
+* Allow do let bindings of newtypes.
+
+### 0.23.1.0
 
 * Add `--show-ghc-calls` and `configShowGhcCalls` to print invocations to GHC.
 
diff --git a/fay.cabal b/fay.cabal
--- a/fay.cabal
+++ b/fay.cabal
@@ -1,5 +1,5 @@
 name:                fay
-version:             0.23.1.0
+version:             0.23.1.1
 synopsis:            A compiler for Fay, a Haskell subset that compiles to JavaScript.
 description:         Fay is a proper subset of Haskell which is type-checked
                      with GHC, and compiled to JavaScript. It is lazy, pure, has a Fay monad,
diff --git a/src/Fay/Compiler/Decl.hs b/src/Fay/Compiler/Decl.hs
--- a/src/Fay/Compiler/Decl.hs
+++ b/src/Fay/Compiler/Decl.hs
@@ -98,9 +98,13 @@
     compilePatBind' pat rhs = do
       exp <- compileExp rhs
       name <- withScopedTmpJsName return
-      [JsIf t b1 []] <- compilePat (JsName name) pat []
-      let err = [throw ("Irrefutable pattern failed for pattern: " ++ prettyPrint pat) (JsList [])]
-      return [JsVar name exp, JsIf t b1 err]
+      m <- compilePat (JsName name) pat []
+      case m of
+        [JsIf t b1 []] -> do
+          let err = [throw ("Irrefutable pattern failed for pattern: " ++ prettyPrint pat) (JsList [])]
+          return [JsVar name exp, JsIf t b1 err]
+        [JsVar n _] -> return [JsVar n exp]
+        x -> error $ "Fay bug! Can't compile pat bind for: " ++ show x
 
 -- | Compile a normal simple pattern binding.
 compileUnguardedRhs :: Bool -> S.X -> S.Name -> S.Exp -> Compile [JsStmt]
diff --git a/tests/doLet.hs b/tests/doLet.hs
--- a/tests/doLet.hs
+++ b/tests/doLet.hs
@@ -7,6 +7,7 @@
   fourth
   fifth
   sixth
+  newtyp
 
 first = do
   let x = 123
@@ -43,3 +44,11 @@
   let y = 777
   print y
   print x
+
+newtype I = I Int
+newtyp = do
+  putStrLn "newtype"
+  I i <- return (I 1)
+  print i
+  let I j = I 2
+  print j
diff --git a/tests/doLet.res b/tests/doLet.res
--- a/tests/doLet.res
+++ b/tests/doLet.res
@@ -11,3 +11,6 @@
 10
 777
 123
+newtype
+1
+2