diff --git a/src/cmake/__tests__/cmake.test.ts b/src/cmake/__tests__/cmake.test.ts
index ed34e78e..97ec26f5 100644
--- a/src/cmake/__tests__/cmake.test.ts
+++ b/src/cmake/__tests__/cmake.test.ts
@@ -1,6 +1,8 @@
 import { setupCmake } from "../cmake"
 import { spawnSync as spawn } from "child_process"
 import { setupTmpDir, cleanupTmpDir } from "../../utils/tests/test-helpers"
+import { addBinExtension } from "../../utils/setup/setupBin"
+import { join } from "path"
 
 jest.setTimeout(100000)
 
@@ -19,7 +21,9 @@ describe("setup-cmake", () => {
     expect(cmakePath).toBeDefined()
     expect(cmakePath).not.toHaveLength(0)
 
-    const { status, error } = spawn(cmakePath, ["--version"], {
+    const cmakeBin = join(cmakePath, addBinExtension("cmake"))
+
+    const { status, error } = spawn(cmakeBin, ["--version"], {
       encoding: "utf8",
     })
     expect(error).toBeUndefined()
diff --git a/src/ninja/__tests__/ninja.test.ts b/src/ninja/__tests__/ninja.test.ts
index af8fa5ad..69249cf4 100644
--- a/src/ninja/__tests__/ninja.test.ts
+++ b/src/ninja/__tests__/ninja.test.ts
@@ -1,6 +1,8 @@
 import { setupNinja } from "../ninja"
 import { spawnSync as spawn } from "child_process"
 import { setupTmpDir, cleanupTmpDir } from "../../utils/tests/test-helpers"
+import { addBinExtension } from "../../utils/setup/setupBin"
+import { join } from "path"
 
 jest.setTimeout(100000)
 
@@ -19,7 +21,9 @@ describe("setup-ninja", () => {
     expect(ninjaPath).toBeDefined()
     expect(ninjaPath).not.toHaveLength(0)
 
-    const { status } = spawn(ninjaPath, ["--version"], {
+    const ninjaBin = join(ninjaPath, addBinExtension("ninja"))
+
+    const { status } = spawn(ninjaBin, ["--version"], {
       encoding: "utf8",
     })
     expect(status).toBe(0)
diff --git a/src/utils/setup/setupBin.ts b/src/utils/setup/setupBin.ts
index 0b2d05a0..a63e48e1 100644
--- a/src/utils/setup/setupBin.ts
+++ b/src/utils/setup/setupBin.ts
@@ -75,3 +75,10 @@ export async function setupPackage(
 
   return installDir
 }
+/** Add bin extension to a binary. This will be `.exe` on Windows. */
+export function addBinExtension(name: string) {
+  if (process.platform === "win32") {
+    return `${name}.exe`
+  }
+  return name
+}