diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -33,14 +33,31 @@
 See [Issues](https://github.com/oleks/remarks/issues) for a roadmap. Feel free
 to add or fix some.
 
+## Installation
+
+[`remarks` is on Hackage](http://hackage.haskell.org/package/remarks), so you
+can just use [Cabal](https://www.haskell.org/cabal/):
+
+```
+$ cabal install remarks
+```
+
+You can also clone this repository and use
+[Stack](https://docs.haskellstack.org/en/stable/README/):
+
+```
+$ stack build
+$ stack install
+```
+
 ## Syntax
 
 A `.mrk` file is a list of judgements.
 
 A judgement starts with a header mark (a sequence of `#`), a title (followed by
 a `:`), given points (followed by `/`), and maximum points (followed by a line
-break). The number of `#` determines the /depth/ of the header, and every file
-/must/ start at depth 1, but may have multiple depth 1 judgements. Headings may
+break). The number of `#` determines the _depth_ of the header, and every file
+_must_ start at depth 1, but may have multiple depth 1 judgements. Headings may
 be arbitrarily nested, but must sum up correctly. For instance, here is a file
 containing only quantitative remarks:
 
@@ -139,7 +156,7 @@
 To support more exotic setups, `remarks` can also work with directories:
 
   * If supplied with a directory path, `remarks` looks for files ending in
-    `.mrk` inside that directory, and comprehends the files, as above, in
+    `.mrk` inside that directory, and comprehends the files as above, in
     lexicographic filename order (e.g.,
     [directory-with-mrk-files](samples/organization/directory-with-mrk-files)).
 
@@ -174,21 +191,4 @@
 $ remarks parse basic.mrk
 $ remarks parse directory-with-mrk-files
 $ remarks parse mixed-directory
-```
-
-## Installation
-
-[`remarks` is on Hackage](http://hackage.haskell.org/package/remarks), so you
-can just use [Cabal](https://www.haskell.org/cabal/):
-
-```
-$ cabal install remarks
-```
-
-You can also clone this repository and use
-[Stack](https://docs.haskellstack.org/en/stable/README/):
-
-```
-$ stack build
-$ stack install
 ```
diff --git a/remarks.cabal b/remarks.cabal
--- a/remarks.cabal
+++ b/remarks.cabal
@@ -1,5 +1,5 @@
 name:                remarks
-version:             0.1.0
+version:             0.1.1
 synopsis:            A DSL for marking student work
 description:         A DSL for marking student work; see README.md for further details.
 homepage:            https://github.com/oleks/remarks#readme
diff --git a/src/Validator.hs b/src/Validator.hs
--- a/src/Validator.hs
+++ b/src/Validator.hs
@@ -28,10 +28,13 @@
 validate j @ (Judgement (h @ (Header (_, p, maxP)), _, subjs)) = do
   try (p <= maxP)
     (PointsExceedMaxPoints h)
-  try ((sum $ map points subjs) ~= p)
-    (BadSubJudgementPointsSum j)
-  try ((sum $ map maxPoints subjs) ~= maxP)
-    (BadSubJudgementMaxPointsSum j)
+  case subjs of
+    [] -> return ()
+    _ -> do
+      try ((sum $ map points subjs) ~= p)
+        (BadSubJudgementPointsSum j)
+      try ((sum $ map maxPoints subjs) ~= maxP)
+        (BadSubJudgementMaxPointsSum j)
   forM_ subjs validate
 
 points :: Judgement -> Double