diff --git a/cli/src/commands/sandbox.ts b/cli/src/commands/sandbox.ts
index fb5cd512..ff1e3c87 100644
--- a/cli/src/commands/sandbox.ts
+++ b/cli/src/commands/sandbox.ts
@@ -288,9 +288,9 @@ function prepare(opts: SandboxBuildOpts): PreparedBuild {
   } else {
     const copies = layer.tools
       .filter((tool) => tool.executablePath)
-      .map((tool) => `COPY tools/${tool.dir}/${tool.binary} /usr/local/bin/${tool.binary}`)
+      .map((tool) => `COPY --chmod=0755 tools/${tool.dir}/${tool.binary} /usr/local/bin/${tool.binary}`)
       .join("\n");
-    dockerfileBody = `FROM ${base}\n${copies}\nRUN chmod -R a+rx /usr/local/bin\n${presenceCheck}`;
+    dockerfileBody = `FROM ${base}\n${copies}\n${presenceCheck}`;
   }
   const dockerfilePath = join(mkdtempSync(join(tmpdir(), "qm-sandbox-")), "Dockerfile");
   writeFileSync(dockerfilePath, dockerfileBody);
diff --git a/cli/test/e2e/sandbox-build.e2e.test.ts b/cli/test/e2e/sandbox-build.e2e.test.ts
index b8874e72..cdaedcc8 100644
--- a/cli/test/e2e/sandbox-build.e2e.test.ts
+++ b/cli/test/e2e/sandbox-build.e2e.test.ts
@@ -17,7 +17,7 @@ test("sandbox build --dry-run generates the COPY-tools Dockerfile + the fly push
     assert.equal(r.code, 0, r.out);
     assert.match(r.out, /DRY RUN — nothing built/);
     assert.match(r.out, /FROM registry\.invalid\/qm\/qm-sandbox-base@sha256:a{64}/);
-    assert.match(r.out, /COPY tools\/example-tool\/example-tool \/usr\/local\/bin\/example-tool/);
+    assert.match(r.out, /COPY --chmod=0755 tools\/example-tool\/example-tool \/usr\/local\/bin\/example-tool/);
     assert.match(r.out, /command -v "\$b"/);
     assert.match(r.out, /docker buildx build --platform linux\/amd64 --load -t acme-sandbox:local/);
   } finally {
diff --git a/cli/test/sandbox-build.test.ts b/cli/test/sandbox-build.test.ts
index 75a052df..f138e8e5 100644
--- a/cli/test/sandbox-build.test.ts
+++ b/cli/test/sandbox-build.test.ts
@@ -56,7 +56,8 @@ test("generates a Dockerfile that COPYs each tool executable onto PATH + bakes t
   try {
     const out = dryRun({ sandboxDir: sb });
     assert.match(out, /FROM registry\.invalid\/qm\/qm-sandbox-base@sha256:a{64}/);
-    assert.match(out, /COPY tools\/example-tool\/example-tool \/usr\/local\/bin\/example-tool/);
+    assert.match(out, /COPY --chmod=0755 tools\/example-tool\/example-tool \/usr\/local\/bin\/example-tool/);
+    assert.doesNotMatch(out, /chmod -R/);
     assert.match(out, /command -v "\$b"/);
     assert.match(out, /'example-tool'/);
     assert.match(out, /acme-sandbox:local/);