diff --git a/test/fixtures/side-effects/core.mjs b/test/fixtures/side-effects/core.mjs
new file mode 100644
index 0000000..aba49fa
--- /dev/null
+++ b/test/fixtures/side-effects/core.mjs
@@ -0,0 +1,2 @@
+import { kind as shimsKind } from "./shims.mjs";
+export { shimsKind };
diff --git a/test/fixtures/side-effects/registry.mjs b/test/fixtures/side-effects/registry.mjs
new file mode 100644
index 0000000..7509569
--- /dev/null
+++ b/test/fixtures/side-effects/registry.mjs
@@ -0,0 +1,9 @@
+export let kind = undefined;
+
+export function setShims(shims) {
+  if (kind) {
+    throw new Error(`shims already set to ${kind}`);
+  }
+
+  kind = shims.kind;
+}
diff --git a/test/fixtures/side-effects/runtime.mjs b/test/fixtures/side-effects/runtime.mjs
new file mode 100644
index 0000000..82f0866
--- /dev/null
+++ b/test/fixtures/side-effects/runtime.mjs
@@ -0,0 +1,5 @@
+export function getRuntime() {
+  return {
+    kind: "node",
+  };
+}
diff --git a/test/fixtures/side-effects/shims.mjs b/test/fixtures/side-effects/shims.mjs
new file mode 100644
index 0000000..415ae47
--- /dev/null
+++ b/test/fixtures/side-effects/shims.mjs
@@ -0,0 +1,8 @@
+import * as shims from "./registry.mjs";
+import * as auto from "./runtime.mjs";
+
+if (!shims.kind) {
+  shims.setShims(auto.getRuntime());
+}
+
+export * from "./registry.mjs";
diff --git a/test/hook/side-effects.mjs b/test/hook/side-effects.mjs
new file mode 100644
index 0000000..7abc0e9
--- /dev/null
+++ b/test/hook/side-effects.mjs
@@ -0,0 +1,4 @@
+import * as core from "../fixtures/side-effects/core.mjs";
+import { strictEqual } from "assert";
+
+strictEqual(core.shimsKind, "node");