diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,4 +1,4 @@
-* v 0.3.1.1 2017-08-15
+* v 0.3.1.2 2017-08-15
   * provided compatible versions of take, drop, length, replicate, splitAt
   * added missing mixed-type subtraction combination to Ring etc.
 
diff --git a/mixed-types-num.cabal b/mixed-types-num.cabal
--- a/mixed-types-num.cabal
+++ b/mixed-types-num.cabal
@@ -1,5 +1,5 @@
 name:           mixed-types-num
-version:        0.3.1.1
+version:        0.3.1.2
 cabal-version:  >= 1.9.2
 build-type:     Simple
 homepage:       https://github.com/michalkonecny/mixed-types-num
diff --git a/src/MixedTypesNumPrelude.hs b/src/MixedTypesNumPrelude.hs
--- a/src/MixedTypesNumPrelude.hs
+++ b/src/MixedTypesNumPrelude.hs
@@ -231,6 +231,16 @@
       Eg @Natural@ and @Float@ are not supported at present,
       but @Double@ is supported.
 
+    * Many common operations such as @fromEnum@, @threadDelay@ give or require
+      an @Int@ value, which means we sometimes need to convert:
+
+      > threadDelay (int 1000000)
+      > integer (fromEnum True)
+
+      Prelude functions such as @take@, @!!@ and @length@ that use @Int@ in Prelude
+      are shadowed in @MixedTypesNumPrelude@ with more compatible/flexible versions.
+      Beware that @Data.List.length@ clashes with @length@ in @MixedTypesNumPrelude@.
+
     * Inferred types can be very large. Eg for @f a b c = sqrt (a + b * c + 1)@ the inferred type is:
 
     >  f: (CanMulAsymmetric t1 t2, CanAddAsymmetric t4 (MulType t1 t2),