diff --git a/mkautodoc/extension.py b/mkautodoc/extension.py
index 7426d99..86e70b3 100644
--- a/mkautodoc/extension.py
+++ b/mkautodoc/extension.py
@@ -182,6 +182,9 @@ def render_signature(
         if inspect.isclass(item):
             qualifier_elem = etree.SubElement(signature_elem, "em")
             qualifier_elem.text = "class "
+        elif inspect.iscoroutinefunction(item):
+            qualifier_elem = etree.SubElement(signature_elem, "em")
+            qualifier_elem.text = "async "
 
         name_elem = etree.SubElement(signature_elem, "code")
         if module_string:
diff --git a/tests/mocklib/mocklib.py b/tests/mocklib/mocklib.py
index 7b70eea..f41bb9b 100644
--- a/tests/mocklib/mocklib.py
+++ b/tests/mocklib/mocklib.py
@@ -24,3 +24,9 @@ def example_property(self):
         """
         This is a property with a *docstring*.
         """
+
+
+async def example_async_function():
+    """
+    This is a coroutine function as can be seen by the *async* keyword.
+    """
diff --git a/tests/test_extension.py b/tests/test_extension.py
index a9db6d0..854d3ee 100644
--- a/tests/test_extension.py
+++ b/tests/test_extension.py
@@ -18,6 +18,18 @@ def test_docstring():
     ]
 
 
+def test_async_function():
+    content = """
+::: mocklib.example_async_function
+"""
+    output = markdown.markdown(content, extensions=["mkautodoc"])
+    assert output.splitlines() == [
+        '<div class="autodoc">',
+        '<div class="autodoc-signature"><em>async </em><code>mocklib.<strong>example_async_function</strong></code><span class="autodoc-punctuation">(</span><span class="autodoc-punctuation">)</span></div>',
+        "</div>",
+    ]
+
+
 def test_members():
     content = """
 # Example