diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,7 @@
+### 0.6.0.0
+
+- Fixed Ellipsoid: constructor expected inverseFlattening and not flattening
+
 ### 0.5.0.0
 
 - Added Benchmarks
diff --git a/jord.cabal b/jord.cabal
--- a/jord.cabal
+++ b/jord.cabal
@@ -1,11 +1,13 @@
--- This file has been generated from package.yaml by hpack version 0.28.2.
+cabal-version: 1.12
+
+-- This file has been generated from package.yaml by hpack version 0.31.1.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 2f1ced38bca95f83cdbb2509dc23645a34c628652e960e7a84e9e1b7b6d4ca8c
+-- hash: a4e2fc2a432aee57ca9f6d714df611ac3368d7470ccda202db3f966a3d6934e4
 
 name:           jord
-version:        0.5.0.0
+version:        0.6.0.0
 synopsis:       Geographical Position Calculations
 description:    Please see the README on GitHub at <https://github.com/ofmooseandmen/jord#readme>
 category:       Geography
@@ -18,10 +20,9 @@
 license:        BSD3
 license-file:   LICENSE
 build-type:     Simple
-cabal-version:  >= 1.10
 extra-source-files:
-    ChangeLog.md
     README.md
+    ChangeLog.md
 
 source-repository head
   type: git
diff --git a/src/Data/Geo/Jord.hs b/src/Data/Geo/Jord.hs
--- a/src/Data/Geo/Jord.hs
+++ b/src/Data/Geo/Jord.hs
@@ -55,4 +55,4 @@
 
 -- | version.
 jordVersion :: String
-jordVersion = "0.5.0.0"
+jordVersion = "0.6.0.0"
diff --git a/src/Data/Geo/Jord/Earth.hs b/src/Data/Geo/Jord/Earth.hs
--- a/src/Data/Geo/Jord/Earth.hs
+++ b/src/Data/Geo/Jord/Earth.hs
@@ -47,7 +47,7 @@
 eccentricity (Ellipsoidal e) = sqrt (1.0 - (b * b) / (a * a))
   where
     a = semiMajorAxis e
-    b = semiMinorAxis a (inverseFlattening e)
+    b = semiMinorAxis a (flattening e)
 eccentricity (Spherical _) = 0
 
 -- | Computes the mean radius of the given 'Earth' model.
@@ -57,7 +57,7 @@
 meanRadius (Ellipsoidal e) = metres ((2.0 * a + b) / 3.0)
   where
     a = semiMajorAxis e
-    b = semiMinorAxis a (inverseFlattening e)
+    b = semiMinorAxis a (flattening e)
 meanRadius (Spherical r) = r
 
 -- | Computes the polar radius or semi-minor axis (b) of the given 'Earth' model.
@@ -65,7 +65,7 @@
 polarRadius (Ellipsoidal e) = metres (semiMinorAxis a f)
   where
     a = semiMajorAxis e
-    f = inverseFlattening e
+    f = flattening e
 polarRadius (Spherical r) = r
 
 -- | Spherical model derived from given model.
@@ -74,15 +74,15 @@
 
 -- | World Geodetic System WGS84 ellipsoid.
 wgs84 :: Earth
-wgs84 = Ellipsoidal (Ellipsoid (metres 6378137.0) (1.0 / 298.257223563))
+wgs84 = Ellipsoidal (Ellipsoid (metres 6378137.0) 298.257223563)
 
 -- | Geodetic Reference System 1980 ellipsoid.
 grs80 :: Earth
-grs80 = Ellipsoidal (Ellipsoid (metres 6378137.0) (1.0 / 298.257222101))
+grs80 = Ellipsoidal (Ellipsoid (metres 6378137.0) 298.257222101)
 
 -- | World Geodetic System WGS72 ellipsoid.
 wgs72 :: Earth
-wgs72 = Ellipsoidal (Ellipsoid (metres 6378135.0) (1.0 / 298.26))
+wgs72 = Ellipsoidal (Ellipsoid (metres 6378135.0) 298.26)
 
 -- | Spherical earth model derived from 'wgs84'.
 s84 :: Earth
@@ -112,6 +112,10 @@
 semiMajorAxis :: Ellipsoid -> Double
 semiMajorAxis = toMetres . equatorialRadius
 
--- | Computes the polar semi-minor axis (b) from @a@ anf @f@.
+-- | Computes the polar semi-minor axis (b) from semi major axis @a@ and flattening @f@.
 semiMinorAxis :: Double -> Double -> Double
 semiMinorAxis a f = a * (1.0 - f)
+
+-- | flattening of ellispoid @e@
+flattening :: Ellipsoid -> Double
+flattening e = 1.0 / inverseFlattening e
diff --git a/src/Data/Geo/Jord/EcefPosition.hs b/src/Data/Geo/Jord/EcefPosition.hs
--- a/src/Data/Geo/Jord/EcefPosition.hs
+++ b/src/Data/Geo/Jord/EcefPosition.hs
@@ -24,7 +24,7 @@
 
 -- | An earth position expressed in the Earth Centred, Earth Fixed (ECEF) coordinates system.
 --
--- @ex-ey@ plane is the equatorial plane, @ey@ is on the prime meridian, and @ez@ on the polar axis.
+-- @ex-ey@ plane is the equatorial plane, @ex@ is on the prime meridian, and @ez@ on the polar axis.
 --
 -- Note: on a spherical model earth, an /n/-vector is equivalent to a normalised version of an (ECEF) cartesian coordinate.
 newtype EcefPosition =