diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # Changelog
 
+- 0.8.6.1 (2020-09-18)
+    * Fix issue with laziness for evaluted code blocks, they should only be
+      evaluated when we actually want to show them
+    * Bump stack resolver to `lts-16.9`
+
 - 0.8.6.0 (2020-09-11)
     * Allow evaluating code blocks (see README for more info)
     * Refactor implementation of fragments
diff --git a/lib/Patat/Eval.hs b/lib/Patat/Eval.hs
--- a/lib/Patat/Eval.hs
+++ b/lib/Patat/Eval.hs
@@ -61,10 +61,10 @@
 --------------------------------------------------------------------------------
 evalBlock :: EvalSettingsMap -> Pandoc.Block -> IO [Instruction Pandoc.Block]
 evalBlock settings orig@(Pandoc.CodeBlock attr@(_, classes, _) txt)
-    | [s@EvalSettings {..}] <- lookupSettings classes settings =
-        unsafeInterleaveIO $ do
-        EvalResult {..} <- evalCode s txt
-        let out = case erExitCode of
+    | [s@EvalSettings {..}] <- lookupSettings classes settings = do
+        out <- unsafeInterleaveIO $ do
+            EvalResult {..} <-  evalCode s txt
+            pure $ case erExitCode of
                 ExitSuccess -> erStdout
                 ExitFailure i ->
                     evalCommand <> ": exit code " <> T.pack (show i) <> "\n" <>
diff --git a/patat.cabal b/patat.cabal
--- a/patat.cabal
+++ b/patat.cabal
@@ -1,5 +1,5 @@
 Name:                patat
-Version:             0.8.6.0
+Version:             0.8.6.1
 Synopsis:            Terminal-based presentations using Pandoc
 Description:         Terminal-based presentations using Pandoc.
 License:             GPL-2