diff --git a/appveyor.yml b/appveyor.yml
index f0d4975f9..c80930781 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -56,6 +56,7 @@ test_script:
       %STACK% setup > nul
       %STACK% path
       echo "" | %STACK% clean
+      echo "" | %STACK% install %STACK_BUILD_OPTS% aeson-pretty --flag=lib-only
       echo "" | %STACK% install %STACK_BUILD_OPTS% pandoc pandoc-citeproc %STACK_FLAGS%
 
 after_test: