diff --git a/pyproject.toml b/pyproject.toml
index 79fe21f..3db7955 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,12 +1,13 @@
 [build-system]
 requires = [
-    "setuptools>=42",
+    "setuptools>=42,<65",
     "wheel",
-    "f90wrap>=0.2.6",
+    "numpy<1.26",
+    "f90wrap<0.3",
     "setuptools_scm[toml]>=3.4"
 ]
 
 build-backend = "setuptools.build_meta"
 
 [tool.setuptools_scm]
-write_to = "f90wrap_pyhmcode/pyhmcode/version.py"
\ No newline at end of file
+write_to = "f90wrap_pyhmcode/pyhmcode/version.py"
diff --git a/setup.py b/setup.py
index b02a73c..d3baf43 100644
--- a/setup.py
+++ b/setup.py
@@ -20,10 +20,32 @@
     long_description = f.read()
 
 def compile_library(env):
+    env = dict(env)
     subprocess.check_call(["make", "f90wrap"], env=env, cwd=HERE)
-    LIB = glob.glob("f90wrap_pyhmcode/_pyhmcode*.so")
-    shutil.copy(LIB[0], "f90wrap_pyhmcode/pyhmcode/",)
 
+    lib = glob.glob(os.path.join(HERE, "f90wrap_pyhmcode", "_pyhmcode*.so"))[0]
+
+    if sys.platform == "darwin":
+        try:
+            out = subprocess.check_output(["otool", "-l", lib], text=True)
+            lines = out.splitlines()
+            rpaths = []
+            for i, line in enumerate(lines):
+                if line.strip() == "cmd LC_RPATH" and i + 2 < len(lines):
+                    path_line = lines[i + 2].strip()
+                    if path_line.startswith("path "):
+                        rpaths.append(path_line.split("path ", 1)[1].rsplit(" (offset", 1)[0])
+
+            seen = set()
+            for rp in rpaths:
+                if rp in seen:
+                    subprocess.check_call(["install_name_tool", "-delete_rpath", rp, lib])
+                else:
+                    seen.add(rp)
+        except Exception as e:
+            print(f"Warning: failed to deduplicate rpaths for {lib}: {e}")
+
+    shutil.copy(lib, "f90wrap_pyhmcode/pyhmcode/")
 
 def copy_utils():
     # There's probably some setuptools magic that could do this cleaner
@@ -99,10 +121,11 @@ def run(self):
                           "Operating System :: OS Independent",],
       package_dir=       {"": "f90wrap_pyhmcode/"},
       packages=          ["pyhmcode"],
-      package_data=      {"pyhmcode": ["_pyhmcode*.so"]},
+      package_data=      {"pyhmcode": ["_pyhmcode*.so", "version.py"]},
+      include_package_data=True,
       # ext_modules       = [Extension('pyhmcode._pyhmcode', [])],
       install_requires=   ["numpy",
-                           "f90wrap"],
+                           "f90wrap<0.3"],
       cmdclass=          {"install":  install,
                           "develop":  develop,
                           "build_py": build,