diff --git a/build-constraints.yaml b/build-constraints.yaml
index c6c03a5e..2ccfc54f 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -1043,7 +1043,7 @@ packages:
         - ghc-events
         - monad-extras
         - optparse-simple
-        - hpack
+        # - hpack # build failure with GHC 8.4 https://github.com/sol/hpack/issues/276
         - bindings-uname
         - stack < 9.9.9
 
@@ -1516,7 +1516,7 @@ packages:
         # - gogol-youtube-analytics
         # - gogol-youtube-reporting
         # - ede # https://github.com/brendanhay/ede/issues/28
-        - pagerduty
+        # - pagerduty # build failure with ghc 8.4 https://github.com/brendanhay/pagerduty/issues/10
         - semver
         - text-manipulate
 
@@ -3271,6 +3271,7 @@ packages:
         - hamtsolo < 0 # build failure with conduit 1.3 https://github.com/tfc/hamtsolo/issues/3
         - hashtables < 0 # build failure with GHC 8.4 https://github.com/gregorycollins/hashtables/issues/45
         - heap < 0 # build failure with GHC 8.4 https://github.com/pruvisto/heap/issues/5
+        - hpack < 0 # build failure with GHC 8.4 https://github.com/sol/hpack/issues/276
         - 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
         - language-docker < 0 # build failure with GHC 8.4 https://github.com/hadolint/language-docker/issues/26
@@ -3278,6 +3279,7 @@ packages:
         - massiv < 0 # build failure with GHC 8.4 https://github.com/lehins/massiv/issues/10
         - 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
         - rainbow < 0 # build failure with GHC 8.4 https://github.com/massysett/rainbow/issues/6
         - type-combinators < 0 # build failure with GHC 8.4 https://github.com/kylcarte/type-combinators/issues/8
         - vinyl < 0 # build failure with GHC 8.4 https://github.com/VinylRecords/Vinyl/issues/114