diff --git a/.circleci/config.yml b/.circleci/config.yml
index f18a4d52d..95cc75a0d 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -149,6 +149,16 @@ jobs:
           command: |
             tools/pytest_wrapper.py packages/test* packages/*/test* -v -k chrome -n 2
 
+  test-emsdk:
+    <<: *defaults
+    steps:
+      - attach_workspace:
+          at: .
+      - run:
+          name: test
+          command: |
+            pytest emsdk/tests -v
+
   test-python:
     <<: *defaults
     steps:
@@ -256,6 +266,9 @@ workflows:
           filters:
             tags:
               only: /.*/
+      - test-emsdk:
+          requires:
+            - build-core
       - test-python:
           filters:
             tags:
diff --git a/Makefile b/Makefile
index 3384607e2..a5407f7ae 100644
--- a/Makefile
+++ b/Makefile
@@ -128,7 +128,7 @@ build/webworker_dev.js: src/webworker.js
 	sed -i -e 's#{{ PYODIDE_BASE_URL }}#./#g' $@
 
 test: all
-	pytest src packages/*/test* pyodide_build -v
+	pytest src emsdk/tests packages/*/test* pyodide_build -v
 
 
 lint:
diff --git a/emsdk/patches/emulate_pointer.patch b/emsdk/patches/emulate_pointer.patch
index 10469bc10..3989c97b1 100644
--- a/emsdk/patches/emulate_pointer.patch
+++ b/emsdk/patches/emulate_pointer.patch
@@ -4,6 +4,8 @@ enabled. This is a simple typo, since `mangled == "_" + symbol`. This piece of
 code is no longer present in upstream master, hence there is no effort to
 upstream the fix.
 
+This patch is tested in emsdk/tests/test_emulate.py
+
 diff --git a/emsdk/fastcomp/emscripten/src/library.js b/emsdk/fastcomp/emscripten/src/library.js
 index 97cca10..5c002d7 100644
 --- a/emsdk/fastcomp/emscripten/src/library.js
diff --git a/emsdk/tests/__init__.py b/emsdk/tests/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/emsdk/tests/common.py b/emsdk/tests/common.py
new file mode 100644
index 000000000..04a297c5a
--- /dev/null
+++ b/emsdk/tests/common.py
@@ -0,0 +1,18 @@
+from pathlib import Path
+import os
+
+EMSDK = Path(__file__).resolve().parents[1] / "emsdk"
+
+path = [
+    str(EMSDK / "node" / "12.18.1_64bit" / "bin"),
+    str(EMSDK / "binaryen" / "bin"),
+    str(EMSDK / "fastcomp" / "emscripten"),
+]
+
+env = {
+    "PATH": ":".join(path) + ":" + os.environ["PATH"],
+    "EMSDK": str(EMSDK),
+    "EM_CONFIG": str(EMSDK / ".emscripten"),
+    "EM_CACHE": str(EMSDK / ".emscripten_cache"),
+    "BINARYEN_ROOT": str(EMSDK / "binaryen"),
+}
diff --git a/emsdk/tests/test_emulate.py b/emsdk/tests/test_emulate.py
new file mode 100644
index 000000000..2ee746ae9
--- /dev/null
+++ b/emsdk/tests/test_emulate.py
@@ -0,0 +1,75 @@
+import subprocess
+from . import common
+
+
+def test_emulate_function(tmpdir):
+    with tmpdir.as_cwd():
+        with open("library.c", "w") as f:
+            f.write(
+                """\
+#include <stdio.h>
+
+void foo() {
+  puts("hello from library");
+}"""
+            )
+        with open("main.c", "w") as f:
+            f.write(
+                """\
+#include <stdio.h>
+#include <dlfcn.h>
+
+int main() {
+  puts("hello from main");
+  void *f = dlopen("library.wasm", RTLD_NOW);
+  if (!f) {
+    puts("cannot load side module");
+    puts(dlerror());
+    return 1;
+  }
+  typedef void (*voidfunc)();
+  voidfunc g = (voidfunc) dlsym(f, "foo");
+  if (!g) {
+    puts("cannot load side function");
+    return 1;
+  } else {
+    g();
+  }
+  return 0;
+}
+"""
+            )
+        subprocess.run(
+            [
+                "emcc",
+                "-s",
+                "SIDE_MODULE=1",
+                "library.c",
+                "-o",
+                "library.wasm",
+                "-s",
+                "EMULATE_FUNCTION_POINTER_CASTS=1",
+                "-s",
+                "EXPORT_ALL=1",
+            ],
+            check=True,
+            env=common.env,
+        )
+        subprocess.run(
+            [
+                "emcc",
+                "-s",
+                "MAIN_MODULE=1",
+                "main.c",
+                "--embed-file",
+                "library.wasm",
+                "-s",
+                "EMULATE_FUNCTION_POINTER_CASTS=1",
+            ],
+            check=True,
+            env=common.env,
+        )
+        out = subprocess.run(
+            ["node", "a.out.js"], capture_output=True, check=True, env=common.env
+        )
+        assert out.stdout == b"hello from main\nhello from library\n"