diff --git a/.github/workflows/dist.yml b/.github/workflows/dist.yml
index 9db0a53..218ce61 100644
--- a/.github/workflows/dist.yml
+++ b/.github/workflows/dist.yml
@@ -81,7 +81,7 @@ jobs:
       run: python setup.py bdist_wheel
     
     - name: Install test dependencies
-      run: python -m pip --disable-pip-version-check install pytest
+      run: python -m pip --disable-pip-version-check install pytest pcpp
     
     - name: Test wheel
       shell: bash
diff --git a/cxxheaderparser/gentest.py b/cxxheaderparser/gentest.py
index b192cea..ace24d7 100644
--- a/cxxheaderparser/gentest.py
+++ b/cxxheaderparser/gentest.py
@@ -6,6 +6,7 @@ import subprocess
 import typing
 
 from .errors import CxxParseError
+from .preprocessor import make_pcpp_preprocessor
 from .options import ParserOptions
 from .simple import parse_string, ParsedData
 
@@ -49,14 +50,23 @@ def nondefault_repr(data: ParsedData) -> str:
     return _inner_repr(data)
 
 
-def gentest(infile: str, name: str, outfile: str, verbose: bool, fail: bool) -> None:
+def gentest(
+    infile: str, name: str, outfile: str, verbose: bool, fail: bool, pcpp: bool
+) -> None:
     # Goal is to allow making a unit test as easy as running this dumper
     # on a file and copy/pasting this into a test
 
     with open(infile, "r") as fp:
         content = fp.read()
 
+    maybe_options = ""
+    popt = ""
+
     options = ParserOptions(verbose=verbose)
+    if options:
+        options.preprocessor = make_pcpp_preprocessor()
+        maybe_options = "options = ParserOptions(preprocessor=make_pcpp_preprocessor())"
+        popt = ", options=options"
 
     try:
         data = parse_string(content, options=options)
@@ -74,15 +84,17 @@ def gentest(infile: str, name: str, outfile: str, verbose: bool, fail: bool) ->
     if not fail:
         stmt = nondefault_repr(data)
         stmt = f"""
-            data = parse_string(content, cleandoc=True)
+            {maybe_options}
+            data = parse_string(content, cleandoc=True{popt})
 
             assert data == {stmt}
         """
     else:
         stmt = f"""
+            {maybe_options}
             err = {repr(err)}
             with pytest.raises(CxxParseError, match=re.escape(err)):
-                parse_string(content, cleandoc=True)
+                parse_string(content, cleandoc=True{popt})
         """
 
     content = ("\n" + content.strip()).replace("\n", "\n              ")
@@ -113,6 +125,7 @@ if __name__ == "__main__":
     parser = argparse.ArgumentParser()
     parser.add_argument("header")
     parser.add_argument("name", nargs="?", default="TODO")
+    parser.add_argument("--pcpp", default=False, action="store_true")
     parser.add_argument("-v", "--verbose", default=False, action="store_true")
     parser.add_argument("-o", "--output", default="-")
     parser.add_argument(
@@ -120,4 +133,4 @@ if __name__ == "__main__":
     )
     args = parser.parse_args()
 
-    gentest(args.header, args.name, args.output, args.verbose, args.fail)
+    gentest(args.header, args.name, args.output, args.verbose, args.fail, args.pcpp)
diff --git a/tests/test_preprocessor.py b/tests/test_preprocessor.py
new file mode 100644
index 0000000..35ed0ab
--- /dev/null
+++ b/tests/test_preprocessor.py
@@ -0,0 +1,27 @@
+from cxxheaderparser.options import ParserOptions
+from cxxheaderparser.preprocessor import make_pcpp_preprocessor
+from cxxheaderparser.simple import NamespaceScope, ParsedData, parse_string
+from cxxheaderparser.types import FundamentalSpecifier, NameSpecifier, PQName, Token, Type, Value, Variable
+
+
+def test_basic_preprocessor() -> None:
+    content = """
+      #define X 1
+      int x = X;
+    """
+    options = ParserOptions(preprocessor=make_pcpp_preprocessor())
+    data = parse_string(content, cleandoc=True, options=options)
+
+    assert data == ParsedData(
+        namespace=NamespaceScope(
+            variables=[
+                Variable(
+                    name=PQName(segments=[NameSpecifier(name="x")]),
+                    type=Type(
+                        typename=PQName(segments=[FundamentalSpecifier(name="int")])
+                    ),
+                    value=Value(tokens=[Token(value="1")]),
+                )
+            ]
+        )
+    )
\ No newline at end of file