diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # spherical
 
+## 0.1.2.2
+
+  * Documentation improvements
+
 ## 0.1.2.1
 
   * Fix `sinc`
diff --git a/spherical.cabal b/spherical.cabal
--- a/spherical.cabal
+++ b/spherical.cabal
@@ -1,6 +1,6 @@
 cabal-version: 1.18
 name: spherical
-version: 0.1.2.1
+version: 0.1.2.2
 license: BSD3
 license-file: LICENSE
 copyright: Copyright: (c) 2018 Vanessa McHale
@@ -35,13 +35,13 @@
     build-depends:
         base >=4.3 && <5,
         composition-prelude -any
-    
+
     if flag(development)
         ghc-options: -Werror
-    
+
     if impl(ghc >=8.0)
         ghc-options: -Wincomplete-uni-patterns -Wincomplete-record-updates
                      -Wredundant-constraints -Widentities
-    
+
     if impl(ghc >=8.4)
         ghc-options: -Wmissing-export-lists
diff --git a/src/Math/Geometry/Spherical.hs b/src/Math/Geometry/Spherical.hs
--- a/src/Math/Geometry/Spherical.hs
+++ b/src/Math/Geometry/Spherical.hs
@@ -147,6 +147,9 @@
 
 -- | Uses areal projection; then finds area of the polygon by the shoelace
 -- method.
+--
+-- This is morally dubious in that it uses the Bonne projection centered around
+-- DC, so it will blow up in some cases.
 areaPolygon :: Floating a
             => a -- ^ Radius of sphere
             -> [(a, a)] -- ^ Polygon on the sphere, with points given in degrees.