diff --git a/pymbolic/interop/maxima.py b/pymbolic/interop/maxima.py
index 77f1aab3892342d40b6941e60d517cd2dd42438d..6021486e954f3ff965236d9f90eba0186de4511f 100644
--- a/pymbolic/interop/maxima.py
+++ b/pymbolic/interop/maxima.py
@@ -326,6 +326,8 @@ class MaximaKernel:
         self._initialize()
 
     def shutdown(self):
+        # tty echo appears to cause waitpid() to block on OS X; turn it off.
+        self.child.setecho(False)
         self._sendline("quit();")
         self.child.wait()