diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 630f6b7ff9c..59a7cb695b1 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -91,6 +91,7 @@ jobs:
           git config --system core.autocrlf false
           git config --system core.eol lf
           git config --system core.longpaths true
+          git config --system core.symlinks true
 
       - name: Checkout
         uses: actions/checkout@v7
@@ -205,20 +206,28 @@ jobs:
       - name: Check for diffs in tests folder
         run: git diff --ignore-cr-at-eol --exit-code tests
 
+      # On Windows, after running setup-ocaml (if it wasn't cached yet or the cache couldn't be restored),
+      # Cygwin bash is used instead of Git Bash for Windows, breaking the test scripts below.
+      # So we need to adjust the path to bring back Git Bash for Windows.
+      - name: "Windows: Use Git Bash"
+        if: ${{ runner.os == 'Windows' }}
+        run: echo "C:\Program Files\Git\bin" >> $GITHUB_PATH
+        shell: bash
+
+      # Git Bash does not include make.
+      - name: "Windows: Install make"
+        if: ${{ runner.os == 'Windows' }}
+        run: command -v make || choco install make --no-progress
+        shell: bash
+
+      # Linux runs these tests in the coverage workflow.
       - name: Run analysis / tools tests
-        if: runner.os != 'Windows' && runner.os != 'Linux'
+        if: runner.os != 'Linux'
         run: opam exec -- make -C tests/analysis_tests test && make -C tests/tools_tests test
+        shell: bash
 
       - name: Run gentype tests
-        if: runner.os != 'Windows'
         run: make -C tests/gentype_tests/typescript-react-example clean test
-
-      # On Windows, after running setup-ocaml (if it wasn't cached yet or the cache couldn't be restored),
-      # Cygwin bash is used instead of Git Bash for Windows, breaking the rewatch tests.
-      # So we need to adjust the path to bring back Git Bash for Windows.
-      - name: Rewatch tests need Git Bash for Windows
-        if: ${{ runner.os == 'Windows' }}
-        run: echo "C:\Program Files\Git\bin" >> $GITHUB_PATH
         shell: bash
 
       - name: Run OCaml rewatch parity tests
diff --git a/analysis/src/cli.ml b/analysis/src/cli.ml
index 2c6f843f5a0..18299e95d07 100644
--- a/analysis/src/cli.ml
+++ b/analysis/src/cli.ml
@@ -209,8 +209,11 @@ let test ~state ~path =
     let lines = text |> String.split_on_char '\n' in
     let process_line i line =
       let create_current_file () =
+        (* Binary mode keeps the copy's LF line endings on Windows, so dumped
+           source text matches the original file. *)
         let current_file, cout =
-          Filename.open_temp_file "def" ("txt." ^ Filename.extension path)
+          Filename.open_temp_file ~mode:[Open_binary] "def"
+            ("txt." ^ Filename.extension path)
         in
         let remove_line_comment l =
           let len = String.length l in
diff --git a/changes/windows-ci-tests.internal.md b/changes/windows-ci-tests.internal.md
new file mode 100644
index 00000000000..0ec69221109
--- /dev/null
+++ b/changes/windows-ci-tests.internal.md
@@ -0,0 +1 @@
+- Run the full compiler unit tests, runtime docstring tests, analysis, tools and gentype tests, and the `unicode` and `duplicated_symlinked_packages` build tests on Windows CI.
diff --git a/lib_dev/paths.js b/lib_dev/paths.js
index b0539d09e5f..b974e6febf9 100644
--- a/lib_dev/paths.js
+++ b/lib_dev/paths.js
@@ -72,6 +72,9 @@ export const compilerBinDir = path.resolve(
 );
 
 /**
- * path: `<projectDir>/_build/install/default/bin/ounit_tests`
+ * path: `<projectDir>/_build/install/default/bin/ounit_tests[.exe]`
  */
-export const ounitTestBin = path.join(compilerBinDir, "ounit_tests");
+export const ounitTestBin = path.join(
+  compilerBinDir,
+  process.platform === "win32" ? "ounit_tests.exe" : "ounit_tests",
+);
diff --git a/scripts/test.js b/scripts/test.js
index 79ca4569583..bd76a7479a3 100644
--- a/scripts/test.js
+++ b/scripts/test.js
@@ -64,35 +64,9 @@ if (formatTest) {
 }
 
 if (ounitTest) {
-  if (process.platform === "win32") {
-    // GenType's drive-root regression needs the native Windows Filename module.
-    const binary = path.join(
-      projectDir,
-      "_build/default/tests/ounit_tests/ounit_tests_main.exe",
-    );
-    const { stdout } = await execBin(binary, ["-list-test"], {
-      shell: false,
-      throwOnFail: true,
-    });
-    const tests = stdout
-      .split(/\r?\n/)
-      .filter(test => test.includes(":gentype:"));
-    if (tests.length === 0) {
-      throw new Error("No GenType unit tests found");
-    }
-    await execBin(
-      binary,
-      tests.flatMap(test => ["-only-test", test]),
-      {
-        stdio: "inherit",
-        shell: false,
-      },
-    );
-  } else {
-    await execBin(ounitTestBin, [], {
-      stdio: "inherit",
-    });
-  }
+  await execBin(ounitTestBin, [], {
+    stdio: "inherit",
+  });
 }
 
 if (mochaTest) {
@@ -197,9 +171,7 @@ if (buildTest) {
 }
 
 if (runtimeDocstrings) {
-  if (process.platform === "win32") {
-    console.log(`Skipping docstrings tests on ${process.platform}`);
-  } else if (process.platform === "darwin" && os.release().startsWith("22")) {
+  if (process.platform === "darwin" && os.release().startsWith("22")) {
     // Workaround for intermittent hangs in CI
     console.log("Skipping docstrings tests on macOS 13");
   } else {
diff --git a/tests/analysis_tests/tests-generic-jsx-transform/Makefile b/tests/analysis_tests/tests-generic-jsx-transform/Makefile
index 4d26df85bb1..d973307f858 100644
--- a/tests/analysis_tests/tests-generic-jsx-transform/Makefile
+++ b/tests/analysis_tests/tests-generic-jsx-transform/Makefile
@@ -4,7 +4,7 @@ build:
 	yarn build
 
 test: build
-	./test.sh
+	bash ./test.sh
 
 clean:
 	yarn clean
diff --git a/tests/analysis_tests/tests-incremental-typechecking/Makefile b/tests/analysis_tests/tests-incremental-typechecking/Makefile
index 6abbf0dd984..3b3d9b0c665 100644
--- a/tests/analysis_tests/tests-incremental-typechecking/Makefile
+++ b/tests/analysis_tests/tests-incremental-typechecking/Makefile
@@ -4,7 +4,7 @@ build:
 	yarn build > /dev/null 2>&1 || true
 
 test: build
-	./test.sh
+	bash ./test.sh
 
 clean:
 	yarn clean
diff --git a/tests/analysis_tests/tests-namespaced-references/Makefile b/tests/analysis_tests/tests-namespaced-references/Makefile
index 2b663dd3475..dfc867973c7 100644
--- a/tests/analysis_tests/tests-namespaced-references/Makefile
+++ b/tests/analysis_tests/tests-namespaced-references/Makefile
@@ -10,7 +10,7 @@ build:
 	cp lib/bs/MyNamespace.cmt lib/bs/___incremental/MyNamespace.cmt
 
 test: build
-	./test.sh
+	bash ./test.sh
 
 clean:
 	yarn clean
diff --git a/tests/analysis_tests/tests-reanalyze/deadcode-benchmark/Makefile b/tests/analysis_tests/tests-reanalyze/deadcode-benchmark/Makefile
index 85b3f706db2..150435a2295 100644
--- a/tests/analysis_tests/tests-reanalyze/deadcode-benchmark/Makefile
+++ b/tests/analysis_tests/tests-reanalyze/deadcode-benchmark/Makefile
@@ -5,7 +5,7 @@ COPIES ?= 50
 
 generate:
 	chmod +x generate.sh
-	./generate.sh $(COPIES)
+	bash ./generate.sh $(COPIES)
 
 node_modules/.bin/rescript:
 	yarn install
diff --git a/tests/analysis_tests/tests-reanalyze/deadcode/Makefile b/tests/analysis_tests/tests-reanalyze/deadcode/Makefile
index 2a1c1a4b95a..24381b4f456 100644
--- a/tests/analysis_tests/tests-reanalyze/deadcode/Makefile
+++ b/tests/analysis_tests/tests-reanalyze/deadcode/Makefile
@@ -4,7 +4,7 @@ build:
 	yarn build
 
 test: build node_modules/.bin/rescript
-	./test.sh
+	bash ./test.sh
 
 # Order-independence test for reanalyze - not run by default (takes longer)
 # Verifies that processing files in different orders produces identical results
diff --git a/tests/analysis_tests/tests-reanalyze/termination/Makefile b/tests/analysis_tests/tests-reanalyze/termination/Makefile
index 18fcea0dc88..03e13de6fc1 100644
--- a/tests/analysis_tests/tests-reanalyze/termination/Makefile
+++ b/tests/analysis_tests/tests-reanalyze/termination/Makefile
@@ -4,7 +4,7 @@ build:
 	yarn build
 
 test: build
-	./test.sh
+	bash ./test.sh
 
 clean:
 	yarn clean
diff --git a/tests/analysis_tests/tests-sourcedirs-dependency/Makefile b/tests/analysis_tests/tests-sourcedirs-dependency/Makefile
index 4d26df85bb1..d973307f858 100644
--- a/tests/analysis_tests/tests-sourcedirs-dependency/Makefile
+++ b/tests/analysis_tests/tests-sourcedirs-dependency/Makefile
@@ -4,7 +4,7 @@ build:
 	yarn build
 
 test: build
-	./test.sh
+	bash ./test.sh
 
 clean:
 	yarn clean
diff --git a/tests/analysis_tests/tests/Makefile b/tests/analysis_tests/tests/Makefile
index 4d26df85bb1..d973307f858 100644
--- a/tests/analysis_tests/tests/Makefile
+++ b/tests/analysis_tests/tests/Makefile
@@ -4,7 +4,7 @@ build:
 	yarn build
 
 test: build
-	./test.sh
+	bash ./test.sh
 
 clean:
 	yarn clean
diff --git a/tests/analysis_tests/tests/test.sh b/tests/analysis_tests/tests/test.sh
index 993782b8678..592d3a6d472 100755
--- a/tests/analysis_tests/tests/test.sh
+++ b/tests/analysis_tests/tests/test.sh
@@ -4,6 +4,8 @@ for file in src/*.{res,resi}; do
   # CI. We use LF, and the CI OCaml fork prints CRLF. Convert.
   if [ "$RUNNER_OS" == "Windows" ]; then
     perl -pi -e 's/\r\n/\n/g' -- $output
+    # Completion data holds a native path. Use the snapshots' separator.
+    perl -pi -e 's{(?<="filePath": ")[^"]*}{$& =~ s#\\\\#/#gr}ge' -- $output
   fi
 done
 
@@ -13,6 +15,8 @@ for file in not_compiled/*.{res,resi}; do
   # CI. We use LF, and the CI OCaml fork prints CRLF. Convert.
   if [ "$RUNNER_OS" == "Windows" ]; then
     perl -pi -e 's/\r\n/\n/g' -- $output
+    # Completion data holds a native path. Use the snapshots' separator.
+    perl -pi -e 's{(?<="filePath": ")[^"]*}{$& =~ s#\\\\#/#gr}ge' -- $output
   fi
 done
 
diff --git a/tests/build_tests/duplicated_symlinked_packages/input.js b/tests/build_tests/duplicated_symlinked_packages/input.js
index 419ac248b13..e41287dcba3 100644
--- a/tests/build_tests/duplicated_symlinked_packages/input.js
+++ b/tests/build_tests/duplicated_symlinked_packages/input.js
@@ -1,6 +1,8 @@
 // @ts-check
 
 import * as assert from "node:assert";
+import * as fs from "node:fs/promises";
+import * as path from "node:path";
 import { runtimePath } from "#cli/runtime";
 import { setup } from "#dev/process";
 
@@ -9,13 +11,23 @@ process.env.RESCRIPT_RUNTIME = runtimePath;
 
 const { execBuild, execClean } = setup(import.meta.dirname);
 
-if (process.platform === "win32") {
-  console.log("Skipping test on Windows");
+// Without core.symlinks, Git on Windows checks the links out as plain files.
+// CI enables it, so only local checkouts may skip.
+const link = await fs.lstat(
+  path.join(import.meta.dirname, "node_modules", "a"),
+);
+if (!link.isSymbolicLink()) {
+  if (process.env.CI) {
+    assert.fail("node_modules/a was not checked out as a symlink");
+  }
+  console.log("Skipping test: symlinks are not checked out as symlinks");
   process.exit(0);
 }
 
 await execClean();
-const { stderr } = await execBuild();
+const { stderr: rawStderr } = await execBuild();
+// Windows joins the package paths with backslashes.
+const stderr = rawStderr.replaceAll("\\", "/");
 
 // c reaches a and b through node_modules symlinks and counts once; z has two
 // copies, node_modules/z and a/node_modules/z, the one duplicate to report.
diff --git a/tests/build_tests/unicode/input.js b/tests/build_tests/unicode/input.js
index 7c68350b899..65693376620 100644
--- a/tests/build_tests/unicode/input.js
+++ b/tests/build_tests/unicode/input.js
@@ -6,11 +6,6 @@ import { setup } from "#dev/process";
 
 const { execBuildOrThrow, execClean } = setup(import.meta.dirname);
 
-if (process.platform === "win32") {
-  console.log("Skipping test on Windows");
-  process.exit(0);
-}
-
 await execBuildOrThrow();
 
 await fs.access(
diff --git a/tests/ounit_tests/ounit_compiler_request_tests.ml b/tests/ounit_tests/ounit_compiler_request_tests.ml
index 8768304d41c..e797dd7404d 100644
--- a/tests/ounit_tests/ounit_compiler_request_tests.ml
+++ b/tests/ounit_tests/ounit_compiler_request_tests.ml
@@ -1604,9 +1604,11 @@ let concurrent_async_context_tests _context =
         write directory "Sync.res" sync_source;
         Domain.spawn (fun () ->
             ignore (Atomic.fetch_and_add ready 1);
-            let deadline = Unix.gettimeofday () +. 5. in
+            (* Sleep rather than spin: each spawn stops the world, and spinning
+               domains outnumbering the cores starve the domain that spawns. *)
+            let deadline = Unix.gettimeofday () +. 30. in
             while Atomic.get ready < 8 && Unix.gettimeofday () < deadline do
-              Domain.cpu_relax ()
+              Unix.sleepf 0.001
             done;
             check (Atomic.get ready = 8) "async requests did not overlap";
             for _ = 1 to 3 do
diff --git a/tests/tools_tests/Makefile b/tests/tools_tests/Makefile
index e8d2c1f3fc5..0105c9f9825 100644
--- a/tests/tools_tests/Makefile
+++ b/tests/tools_tests/Makefile
@@ -4,7 +4,7 @@ build:
 	yarn build
 
 test: build
-	./test.sh
+	bash ./test.sh
 	yarn build
 
 clean:
diff --git a/tests/tools_tests/test.sh b/tests/tools_tests/test.sh
index 0a735d74b0f..928e575663f 100755
--- a/tests/tools_tests/test.sh
+++ b/tests/tools_tests/test.sh
@@ -13,9 +13,16 @@ for file in src/*.{res,resi}; do
   fi
 done
 
+# bsc runs the PPX command through the system shell, and cmd.exe needs
+# backslashes in the program path.
+ppx_command="../../_build/install/default/bin/rescript-tools ppx"
+if [ "${RUNNER_OS:-}" == "Windows" ]; then
+  ppx_command='..\..\_build\install\default\bin\rescript-tools.exe ppx'
+fi
+
 for file in ppx/*.res; do
   output="src/expected/$(basename $file).jsout"
-  ../../cli/bsc.js -ppx "../../_build/install/default/bin/rescript-tools ppx" $file > $output
+  ../../cli/bsc.js -ppx "$ppx_command" $file > $output
   if [ "${RUNNER_OS:-}" == "Windows" ]; then
     perl -pi -e 's/\r\n/\n/g' -- $output
   fi