diff --git a/.ci/build.sh b/.ci/build.sh
index 93246b68cc..e396f3a98c 100755
--- a/.ci/build.sh
+++ b/.ci/build.sh
@@ -22,6 +22,11 @@ if [[ "$GHC_HEAD" != "yes" ]]; then
 fi
 set -u
 
+cabal v2-build clash-prelude --write-ghc-environment-files=always
+# Undo mmap crash workaround for clash-cosim, see PR #2572.
+# It uses a custom setup, which can't be linked with -rtsopts
+GHCRTS="" cabal v2-build clash-cosim --write-ghc-environment-files=always
+
 # Build with default constraints
 cabal v2-build all --write-ghc-environment-files=always
 
diff --git a/.ci/cabal.project.local b/.ci/cabal.project.local
index cbcefd77a6..40cb9fda64 100644
--- a/.ci/cabal.project.local
+++ b/.ci/cabal.project.local
@@ -10,7 +10,7 @@ package *
 
 package clash-prelude
   ghc-options: -Werror
-  flags: +doctests -workaround-ghc-mmap-crash
+  flags: +doctests
   tests: True
   benchmarks: True
 
@@ -24,7 +24,6 @@ package clash-lib
 
 package clash-ghc
   ghc-options: -Werror
-  flags: -workaround-ghc-mmap-crash
 
 package clash-cosim
   ghc-options: -Werror
@@ -48,7 +47,7 @@ package clash-lib-hedgehog
 package clash-testsuite
   ghc-options: -Werror
   -- enable cosim
-  flags: +cosim -workaround-ghc-mmap-crash
+  flags: +cosim
 
 package clash-benchmark
   ghc-options: -Werror
diff --git a/.ci/gitlab/common.yml b/.ci/gitlab/common.yml
index 2e867da790..2c4000efbd 100644
--- a/.ci/gitlab/common.yml
+++ b/.ci/gitlab/common.yml
@@ -21,6 +21,8 @@
   before_script:
     - export THREADS=$(./.ci/effective_cpus.sh)
     - export CABAL_JOBS=$(./.ci/effective_cpus.sh)
+    - export CABAL_DIR=$HOME/.cabal
+    - if [[ "$WORKAROUND_GHC_MMAP_CRASH" == "yes" ]]; then export GHCRTS="-xm20000000"; fi
     - export
     - tar -xf cache.tar.zst -C / || true
     - .ci/setup.sh
diff --git a/.ci/gitlab/test.yml b/.ci/gitlab/test.yml
index 9cb4ec252b..c8ebd618ee 100644
--- a/.ci/gitlab/test.yml
+++ b/.ci/gitlab/test.yml
@@ -37,6 +37,7 @@ stages:
     - export CABAL_JOBS=$(./.ci/effective_cpus.sh)
     - export clash_lib_datadir=$(pwd)/clash-lib/
     - export clash_cosim_datadir=$(pwd)/clash-cosim/
+    - if [[ "$WORKAROUND_GHC_MMAP_CRASH" == "yes" ]]; then export GHCRTS="-xm20000000"; fi
     - export
     - tar -xf cache.tar.zst -C / || true
     - tar -xf dist.tar.zst -C /
diff --git a/.ci/setup.sh b/.ci/setup.sh
index bdd41c8af8..9ef5489702 100755
--- a/.ci/setup.sh
+++ b/.ci/setup.sh
@@ -78,10 +78,6 @@ if [ ! -f cabal.project.local ]; then
   fi
 
   set +u
-  if [[ "$WORKAROUND_GHC_MMAP_CRASH" == "yes" ]]; then
-    sed -i 's/-workaround-ghc-mmap-crash/+workaround-ghc-mmap-crash/g' cabal.project.local
-  fi
-
   if [[ "$GHC_HEAD" == "yes" ]]; then
     cat .ci/cabal.project.local.append-HEAD >> cabal.project.local
   fi
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 088d8fc7ce..f8d5d4eb14 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -126,7 +126,7 @@ jobs:
         CABAL_JOBS: 2
         MULTIPLE_HIDDEN: ${{ matrix.multiple_hidden }}
         CI_COMMIT_BRANCH: ${{ github.base_ref }}
-        WORKAROUND_GHC_MMAP_CRASH: ${{ matrix.workaround_ghc_mmap_crash }}
+        GHCRTS: ${{ fromJSON('["","-xm20000000"]')[matrix.workaround_ghc_mmap_crash == 'yes'] }}
 
     steps:
       - name: Checkout
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 691798ab39..0fa2d04bf9 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -53,6 +53,7 @@ nix-build:
   needs: []
   stage: test
   before_script:
+   - if [[ "$WORKAROUND_GHC_MMAP_CRASH" == "yes" ]]; then export GHCRTS="-xm20000000"; fi
    - nix-env -i gawk
   script:
     - nix-build -j$(./.ci/effective_cpus.sh)
diff --git a/benchmark/profiling/prepare/clash-profiling-prepare.cabal b/benchmark/profiling/prepare/clash-profiling-prepare.cabal
index 033d38e57b..331b1c4b0e 100644
--- a/benchmark/profiling/prepare/clash-profiling-prepare.cabal
+++ b/benchmark/profiling/prepare/clash-profiling-prepare.cabal
@@ -26,7 +26,7 @@ library
 executable clash-profile-normalization-prepare
   main-is:             profile-normalization-prepare.hs
   default-language:    Haskell2010
-  ghc-options:         -Wall -Wcompat
+  ghc-options:         -Wall -Wcompat -rtsopts
   build-depends:       base,
                        binary,
                        bytestring,
@@ -38,7 +38,7 @@ executable clash-profile-normalization-prepare
 executable clash-profile-netlist-prepare
   main-is:             profile-netlist-prepare.hs
   default-language:    Haskell2010
-  ghc-options:         -Wall -Wcompat
+  ghc-options:         -Wall -Wcompat -rtsopts
   build-depends:       base,
                        binary,
                        bytestring,
diff --git a/benchmark/profiling/run/clash-profiling.cabal b/benchmark/profiling/run/clash-profiling.cabal
index 6730b634e2..6b8fad1fc6 100644
--- a/benchmark/profiling/run/clash-profiling.cabal
+++ b/benchmark/profiling/run/clash-profiling.cabal
@@ -12,7 +12,7 @@ cabal-version:       >=1.10
 executable clash-profile-normalization-run
   main-is:             profile-normalization-run.hs
   default-language:    Haskell2010
-  ghc-options:         -O2 -Wall -Wcompat
+  ghc-options:         -O2 -Wall -Wcompat -rtsopts
   build-depends:       base,
                        binary,
                        bytestring,
@@ -30,7 +30,7 @@ executable clash-profile-normalization-run
 executable clash-profile-netlist-run
   main-is:             profile-netlist-run.hs
   default-language:    Haskell2010
-  ghc-options:         -O2 -Wall -Wcompat
+  ghc-options:         -O2 -Wall -Wcompat -rtsopts
   build-depends:       base,
                        binary,
                        bytestring,
diff --git a/clash-cores/clash-cores.cabal b/clash-cores/clash-cores.cabal
index b9e5a5ecc0..e595021993 100644
--- a/clash-cores/clash-cores.cabal
+++ b/clash-cores/clash-cores.cabal
@@ -99,7 +99,7 @@ test-suite unittests
   hs-source-dirs: test
   type: exitcode-stdio-1.0
   main-is: unittests.hs
-
+  ghc-options: -rtsopts
   if !flag(unittests)
     buildable: False
 
diff --git a/clash-cosim/clash-cosim.cabal b/clash-cosim/clash-cosim.cabal
index 681ceec30f..af4ceb5a49 100644
--- a/clash-cosim/clash-cosim.cabal
+++ b/clash-cosim/clash-cosim.cabal
@@ -116,6 +116,6 @@ test-suite test
       tasty-hunit,
       tasty-quickcheck,
       template-haskell
-  ghc-options:   -Wall -Wcompat
+  ghc-options:   -Wall -Wcompat -rtsopts
   if flag(pedantic)
     ghc-options: -Werror
diff --git a/clash-ghc/clash-ghc.cabal b/clash-ghc/clash-ghc.cabal
index 443eb37934..f3db38fb16 100644
--- a/clash-ghc/clash-ghc.cabal
+++ b/clash-ghc/clash-ghc.cabal
@@ -65,24 +65,12 @@ flag use-ghc-paths
   default: False
   manual: True
 
-flag workaround-ghc-mmap-crash
-  description:
-    Only use this flag when hit by GHC bug #19421. See clash-compiler PR #2444.
-  default: False
-  manual: True
-
 executable clash
   Main-Is:            src-ghc/Batch.hs
   Build-Depends:      base, clash-ghc
-  GHC-Options:        -Wall -Wcompat -threaded -rtsopts
+  GHC-Options:        -Wall -Wcompat -threaded -rtsopts -with-rtsopts=-A128m
   if flag(dynamic)
     GHC-Options: -dynamic
-  -- Note that multiple -with-rtsopts are not cumulative, so we can't add the
-  -- common RTS options in the unconditional GHC-Options
-  if flag(workaround-ghc-mmap-crash)
-    GHC-Options: "-with-rtsopts=-A128m -xm20000000"
-  else
-    GHC-Options: -with-rtsopts=-A128m
   extra-libraries:    pthread
   default-language:   Haskell2010
 
diff --git a/clash-lib/clash-lib.cabal b/clash-lib/clash-lib.cabal
index 8bd2e56b02..553f53c28a 100644
--- a/clash-lib/clash-lib.cabal
+++ b/clash-lib/clash-lib.cabal
@@ -315,7 +315,7 @@ executable v16-upgrade-primitives
     directory,
     stringsearch,
     Glob
-  GHC-Options:        -Wall -Wcompat
+  GHC-Options:        -Wall -Wcompat -rtsopts
   default-language:   Haskell2010
 
 test-suite unittests
@@ -323,7 +323,7 @@ test-suite unittests
   type:             exitcode-stdio-1.0
   default-language: Haskell2010
   main-is:          unittests.hs
-  ghc-options:      -Wall -Wcompat -threaded -with-rtsopts=-N
+  ghc-options:      -Wall -Wcompat -threaded -rtsopts -with-rtsopts=-N
   hs-source-dirs:   tests
 
   if !flag(unittests)
diff --git a/clash-prelude/clash-prelude.cabal b/clash-prelude/clash-prelude.cabal
index 3cd17047fe..c197fd499b 100644
--- a/clash-prelude/clash-prelude.cabal
+++ b/clash-prelude/clash-prelude.cabal
@@ -117,12 +117,6 @@ flag benchmarks
   default: True
   manual: True
 
-flag workaround-ghc-mmap-crash
-  description:
-    Only use this flag when hit by GHC bug #19421. See clash-compiler PR #2444.
-  default: False
-  manual: True
-
 common common-options
   default-language:   Haskell2010
   default-extensions: BangPatterns
@@ -367,7 +361,7 @@ test-suite doctests
   type:             exitcode-stdio-1.0
   default-language: Haskell2010
   main-is:          doctests.hs
-  ghc-options:      -Wall -Wcompat -threaded
+  ghc-options:      -Wall -Wcompat -threaded -rtsopts
   hs-source-dirs:   tests
 
   if !flag(doctests)
@@ -379,15 +373,11 @@ test-suite doctests
       doctest-parallel >= 0.2 && < 0.4,
       filepath
 
-  if flag(workaround-ghc-mmap-crash)
-    ghc-options:    -with-rtsopts=-xm20000000
-
-
 test-suite unittests
   import:           common-options
   type:             exitcode-stdio-1.0
   main-is:          unittests.hs
-  ghc-options:      -Wall -Wcompat -threaded -with-rtsopts=-N
+  ghc-options:      -Wall -Wcompat -threaded -rtsopts -with-rtsopts=-N
   hs-source-dirs:   tests
 
   if !flag(unittests)
@@ -451,7 +441,7 @@ benchmark benchmark-clash-prelude
   type:             exitcode-stdio-1.0
   default-language: Haskell2010
   main-is:          benchmark-main.hs
-  ghc-options:      -O2 -Wall
+  ghc-options:      -O2 -Wall -rtsopts
   hs-source-dirs:   benchmarks
 
   ghc-options:      -with-rtsopts=-T
diff --git a/clash-term/clash-term.cabal b/clash-term/clash-term.cabal
index 463cc718c9..5c46722769 100644
--- a/clash-term/clash-term.cabal
+++ b/clash-term/clash-term.cabal
@@ -30,7 +30,7 @@ executable clash-term
                       bytestring        >= 0.10.0.2 && < 0.11,
                       rewrite-inspector == 0.1.0.11
 
-  GHC-Options:        -Wall -Wcompat -threaded
+  GHC-Options:        -Wall -Wcompat -threaded -rtsopts
   extra-libraries:    pthread
   default-language:   Haskell2010
   if os(windows)
diff --git a/tests/clash-testsuite.cabal b/tests/clash-testsuite.cabal
index 18031b4e6f..dcd80597f0 100644
--- a/tests/clash-testsuite.cabal
+++ b/tests/clash-testsuite.cabal
@@ -28,12 +28,6 @@ flag multiple-hidden
   default: False
   manual: True
 
-flag workaround-ghc-mmap-crash
-  description:
-    Only use this flag when hit by GHC bug #19421. See clash-compiler PR #2444.
-  default: False
-  manual: True
-
 common basic-config
   default-language: Haskell2010
   ghc-options: -Wall -Wcompat
@@ -82,9 +76,6 @@ common basic-config
   if flag(multiple-hidden)
     cpp-options:       -DCLASH_MULTIPLE_HIDDEN
 
-  if flag(workaround-ghc-mmap-crash)
-    cpp-options:       -DCLASH_WORKAROUND_GHC_MMAP_CRASH
-
 library
   import: basic-config
   hs-source-dirs:
@@ -127,6 +118,7 @@ library
 executable clash-testsuite
   import:              basic-config
   main-is:             Main.hs
+  ghc-options: -rtsopts
 
   build-tool-depends:
     clash-ghc:clash
diff --git a/tests/src/Test/Tasty/Clash.hs b/tests/src/Test/Tasty/Clash.hs
index 045996c601..c8d55a2df5 100644
--- a/tests/src/Test/Tasty/Clash.hs
+++ b/tests/src/Test/Tasty/Clash.hs
@@ -285,6 +285,7 @@ instance IsTest ClashBinaryTest where
       , "-main-is", cbModName <> ".main" <> show cbBuildTarget
       , "-o", oDir </> "out"
       , "-outputdir", oDir
+      , "-rtsopts"
       ] <> cbExtraBuildArgs <>
       [ cbSourceDirectory </> cbModName <.> "hs"
       ]