diff --git a/install.py b/install.py
index b47188c..e2d51a4 100644
--- a/install.py
+++ b/install.py
@@ -59,7 +59,7 @@ def install_fa2(compile=False, ci=False):
         env = os.environ.copy()
         # limit max jobs to save memory in CI
         if ci:
-            env["MAX_JOBS"] = 4
+            env["MAX_JOBS"] = "4"
         FA2_PATH = REPO_PATH.joinpath("submodules", "flash-attention")
         cmd = [sys.executable, "setup.py", "install"]
         subprocess.check_call(cmd, cwd=str(FA2_PATH.resolve()), env=env)
@@ -74,7 +74,7 @@ def install_fa3(ci=False):
     env = os.environ.copy()
     # limit max jobs to save memory in CI
     if ci:
-        env["MAX_JOBS"] = 4
+        env["MAX_JOBS"] = "4"
     cmd = [sys.executable, "setup.py", "install"]
     subprocess.check_call(cmd, cwd=str(FA3_PATH.resolve()), env=env)