diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,8 @@
     functions in terms of it.
 *   Drop support for GHC 8.2 and lower.
 
+*   *0.1.8.1*: Exported `marginal` again; it was unexported by mistake.
+
 Version 0.1.7.0
 ---------------
 
diff --git a/emd.cabal b/emd.cabal
--- a/emd.cabal
+++ b/emd.cabal
@@ -4,10 +4,10 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: c0f737436b3fc56e2ddc33d92a633b37bc7c6f9486dca2a171480a0d3908dcfa
+-- hash: be01f23a1a945a33db65038fddfc7d9e9ea82364789729d8dc38eec68d5745e1
 
 name:           emd
-version:        0.1.8.0
+version:        0.1.8.1
 synopsis:       Empirical Mode Decomposition and Hilbert-Huang Transform
 description:    Empirical Mode decomposition and Hilbert-Huang Transform in pure
                 Haskell.
diff --git a/src/Numeric/HHT.hs b/src/Numeric/HHT.hs
--- a/src/Numeric/HHT.hs
+++ b/src/Numeric/HHT.hs
@@ -37,7 +37,7 @@
   -- ** Hilbert-Huang Spectrum
   , hhtSpectrum, hhtSparseSpectrum, hhtDenseSpectrum
   -- ** Properties of spectrum
-  , meanMarginal, meanMarginal, instantaneousEnergy, degreeOfStationarity
+  , meanMarginal, marginal, instantaneousEnergy, degreeOfStationarity
   , expectedFreq, dominantFreq
   , foldFreq
   -- ** Options