diff --git a/.buildkite/primer-wasm.yaml b/.buildkite/primer-wasm.yaml
deleted file mode 100644
index 5deaa9577..000000000
--- a/.buildkite/primer-wasm.yaml
+++ /dev/null
@@ -1,41 +0,0 @@
-# Note: because they take so much time to run, we only run the Primer
-# Wasm tests when one of these conditions is true:
-#
-# 1. The PR has hit the merge queue.
-# 2. The PR has the "Run Wasm tests" label.
-
-agents:
-  queue: "nix-build"
-  os: "linux"
-
-steps:
-  # Note: only one of these should run during any given build.
-  # Unfortunately, Buildkite doesn't support if-else conditionals, so
-  # this gets a bit tricky.
-
-  - label: ":haskell: :linux: Primer Wasm tests"
-    if: |
-      build.branch =~ /^gh-readonly-queue\// ||
-      build.pull_request.labels includes "Run Wasm tests"
-    command: |
-      nix develop .#wasm --print-build-logs --command make -f Makefile.wasm32 update
-      nix develop .#wasm --print-build-logs --command make -f Makefile.wasm32 frontend-prod
-      nix develop .#wasm --print-build-logs --command make -f Makefile.wasm32 test
-
-  - label: ":haskell: :linux: Primer Wasm build"
-    if: |
-      build.branch !~ /^gh-readonly-queue\// &&
-      !(build.pull_request.labels includes "Run Wasm tests")
-    command: |
-      nix develop .#wasm --print-build-logs --command make -f Makefile.wasm32 update
-      nix develop .#wasm --print-build-logs --command make -f Makefile.wasm32 frontend-prod
-
-  - label: ":haskell: :macos: Primer Wasm build"
-    if: |
-      build.branch !~ /^gh-readonly-queue\// &&
-      !(build.pull_request.labels includes "Run Wasm tests")
-    command: |
-      nix develop --no-sandbox .#wasm --print-build-logs --command make -f Makefile.wasm32 update
-      nix develop --no-sandbox .#wasm --print-build-logs --command make -f Makefile.wasm32 frontend-prod
-    agents:
-      os: "darwin"
diff --git a/cabal.project b/cabal.project
index 0c79a448a..81e152ef7 100644
--- a/cabal.project
+++ b/cabal.project
@@ -56,6 +56,14 @@ source-repository-package
   tag: ba94173bd8ff22110e65beb51c66cdf1172ce677
   --sha256: 0nqdmxddmcd5c74mbw7yxsg8849rfmvaqq8afmw6ap8qfzr7dax2
 
+-- Upstream requires `happy` at build time, which doesn't work on Wasm
+-- targets.
+source-repository-package
+  type: git
+  location: https://github.com/hackworthltd/pretty-show
+  tag: 91d119cb0e3c5f7d866589b25158739580c8fc88
+  --sha256: sha256-mu8Eq0Sg6nCF8C2sXB6ebZcLhz8TVZAbNMiorA7RVc8=
+
 -- Wasm workarounds.
 --
 -- We would prefer that these workarounds were not Wasm-dependent;
@@ -68,11 +76,3 @@ source-repository-package
 if arch(wasm32)
   -- Required for TemplateHaskell support on Wasm targets.
   shared: True
-
-  -- Upstream requires `happy` at build time, which doesn't work on Wasm
-  -- targets.
-  source-repository-package
-    type: git
-    location: https://github.com/hackworthltd/pretty-show
-    tag: 91d119cb0e3c5f7d866589b25158739580c8fc88
-    --sha256: sha256-mu8Eq0Sg6nCF8C2sXB6ebZcLhz8TVZAbNMiorA7RVc8=
diff --git a/flake.nix b/flake.nix
index b00eb81dc..41213dbf0 100644
--- a/flake.nix
+++ b/flake.nix
@@ -85,7 +85,9 @@
           # haskell.nix does a lot of heavy lifiting for us and gives us a
           # flake for our Cabal project with the following attributes:
           # `checks`, `apps`, and `packages`.
-          primerFlake = pkgs.primer.flake { };
+          primerFlake = pkgs.primer.flake {
+            crossPlatforms = p: [ p.wasi32 ];
+          };
 
           weeder =
             let
@@ -102,7 +104,7 @@
               getHIEs = package:
                 getLibHIE package
                 ++ pkgs.lib.concatMap (getHIE package)
-                  [ "benchmarks" "exes" "sublibs" "tests" ];
+                  [ "exes" "sublibs" "tests" ];
               primer-packages = pkgs.haskell-nix.haskellLib.selectProjectPackages pkgs.primer;
             in
             pkgs.runCommand "weeder"
@@ -193,15 +195,9 @@
             };
           };
 
-          packages = {
-            inherit (pkgs) primer-benchmark;
-          }
-          // (pkgs.lib.optionalAttrs (system == "x86_64-linux") {
-            inherit (pkgs) primer-benchmark-results-json;
-            inherit (pkgs) primer-criterion-results-github-action-benchmark;
-            inherit (pkgs) primer-benchmark-results-github-action-benchmark;
-          })
-          // primerFlake.packages;
+          packages = { }
+            // (pkgs.lib.optionalAttrs (system == "x86_64-linux") { })
+            // primerFlake.packages;
 
           checks = {
             # Disabled, as it doesn't currently build with Nix.
@@ -251,9 +247,7 @@
                 program = "${pkg}/bin/${script}";
               };
             in
-            (pkgs.lib.mapAttrs (name: pkg: mkApp pkg name) {
-              inherit (pkgs) primer-benchmark;
-            })
+            (pkgs.lib.mapAttrs (name: pkg: mkApp pkg name) { })
             // primerFlake.apps;
 
           treefmt.config =
@@ -362,10 +356,6 @@
                           ghcOptions = [ "-Werror" ];
                           preCheck = preCheckTasty;
                         };
-                        primer-benchmark = {
-                          ghcOptions = [ "-Werror" ];
-                          preCheck = preCheckTasty;
-                        };
                       };
                   }
                   {
@@ -400,7 +390,6 @@
                     packages.bytestring-builder.writeHieFiles = false;
                     packages.fail.writeHieFiles = false;
                     packages.diagrams.writeHieFiles = false;
-                    packages.happy-lib.writeHieFiles = false;
                   }
                   {
                     #TODO This shouldn't be necessary - see the commented-out `build-tool-depends` in primer.cabal.
@@ -418,12 +407,13 @@
                     {
                       packages.primer.components.tests.primer-test.testFlags = hide-successes ++ size-cutoff;
                       packages.primer-api.components.tests.primer-api-test.testFlags = hide-successes ++ size-cutoff;
-                      packages.primer-benchmark.components.tests.primer-benchmark-test.testFlags = hide-successes;
                     }
                   )
                 ];
 
                 shell = {
+                  crossPlatforms = p: [ p.wasi32 ];
+
                   # We're using a `source-repository-package`, so we must disable this.
                   # See:
                   # https://github.com/hackworthltd/primer/issues/876
@@ -468,34 +458,9 @@
                 };
               };
 
-              primerFlake = primer.flake { };
-
-              # Note: these benchmarks should only be run (in CI) on a
-              # "benchmark" machine. This is enforced for our CI system
-              # via Nix's `requiredSystemFeatures`.
-              #
-              # The `lastEnvChange` value is an impurity that we can
-              # modify when we want to force a new benchmark run
-              # despite the benchmarking code not having changed, as
-              # otherwise Nix will cache the results. It's intended to
-              # be used to track changes to the benchmarking
-              # environment, such as changes to hardware, that Nix
-              # doesn't know about.
-              #
-              # The value should be formatted as an ISO date, followed
-              # by a "." and a 2-digit monotonic counter, to allow for
-              # multiple changes on the same date. We store this value
-              # in a `lastEnvChange` file in the derivation output, so
-              # that we can examine results in the Nix store and know
-              # which benchmarking environment was used to generate
-              # them.
-              benchmarks =
-                let
-                  lastEnvChange = "20240408.02";
-                in
-                final.callPackage ./nix/pkgs/benchmarks {
-                  inherit lastEnvChange;
-                };
+              primerFlake = primer.flake {
+                crossPlatforms = p: [ p.wasi32 ];
+              };
             in
             {
               lib = (prev.lib or { }) // {
@@ -506,12 +471,6 @@
 
               inherit primer;
 
-              primer-benchmark = primerFlake.packages."primer-benchmark:bench:primer-benchmark";
-
-              inherit (benchmarks) primer-benchmark-results-json;
-              inherit (benchmarks) primer-criterion-results-github-action-benchmark;
-              inherit (benchmarks) primer-benchmark-results-github-action-benchmark;
-
               inherit (ghc982Tools) cabal-fmt hlint ghcid;
             }
           );