diff --git a/build-constraints.yaml b/build-constraints.yaml
index 053a6ec9..d8cf03a3 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -317,7 +317,7 @@ packages:
         - conduit-combinators
         - conduit-extra
         - hebrew-time
-        # - markdown # build failure with ghc 8.4 https://github.com/snoyberg/markdown/issues/38
+        - markdown
         - mime-mail
         - mime-mail-ses
         - network-conduit-tls
@@ -3285,7 +3285,6 @@ packages:
         - hw-fingertree-strict < 0 # build failure with GHC 8.4 https://hub.darcs.net/ross/fingertree/issue/5
         - inline-c < 0 # build failure with GHC 8.4 https://github.com/fpco/inline-c/issues/73
         - list-t < 0 # build failure with GHC 8.4 # https://github.com/nikita-volkov/list-t/issues/12
-        - markdown < 0 # build failure with GHC 8.4 https://github.com/snoyberg/markdown/issues/38
         - monoid-subclasses < 0 # build failure with GHC 8.4 https://github.com/blamario/monoid-subclasses/issues/16
         - n-tuple < 0 # build failure with GHC 8.4 https://github.com/athanclark/n-tuple/issues/1
         - pagerduty < 0 # build failure with GHC 8.4 https://github.com/brendanhay/pagerduty/issues/10