diff --git a/setup.py b/setup.py
index a0e9b205..031172e2 100644
--- a/setup.py
+++ b/setup.py
@@ -52,7 +52,7 @@ def find_package_modules(self, package, package_dir):
 setup(
     ext_modules=[
         Pybind11Extension(
-            "ml_dtypes._ml_dtypes_lib",
+            "ml_dtypes._ml_dtypes_ext",
             [
                 "ml_dtypes/_src/dtypes.cc",
                 "ml_dtypes/_src/numpy.cc",