diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,10 @@
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## 0.18.6
+### Removed
+- Follow Stack advise removing `-O2` GHC option.
+
 ## 0.18.5
 ### Added
 - Compatibility with SegWit on extended public key endpoints.
diff --git a/haskoin-store.cabal b/haskoin-store.cabal
--- a/haskoin-store.cabal
+++ b/haskoin-store.cabal
@@ -4,10 +4,10 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 4d53e327a8c580ccce1a66b1432e4aa13042697403d4dd56a2fb99137d2e2213
+-- hash: c3af87052093a111e194094e0f6eff46423b80b4faaf280b24ce623b56c19445
 
 name:           haskoin-store
-version:        0.18.5
+version:        0.18.6
 synopsis:       Storage and index for Bitcoin and Bitcoin Cash
 description:    Store blocks, transactions, and balances for Bitcoin or Bitcoin Cash, and make that information via REST API.
 category:       Bitcoin, Finance, Network
@@ -83,7 +83,7 @@
       Paths_haskoin_store
   hs-source-dirs:
       app
-  ghc-options: -threaded -rtsopts -with-rtsopts=-N -O2
+  ghc-options: -threaded -rtsopts -with-rtsopts=-N
   build-depends:
       aeson
     , base >=4.9 && <5
@@ -128,7 +128,7 @@
       Paths_haskoin_store
   hs-source-dirs:
       test
-  ghc-options: -threaded -rtsopts -with-rtsopts=-N -O2
+  ghc-options: -threaded -rtsopts -with-rtsopts=-N
   build-depends:
       aeson
     , base >=4.9 && <5