diff --git a/etc/rebuild-cython.sh b/etc/rebuild-cython.sh
index 8be2da78..49ffa1a7 100755
--- a/etc/rebuild-cython.sh
+++ b/etc/rebuild-cython.sh
@@ -1,3 +1,8 @@
 #!/bin/bash
-find zipline tests -regex '.*\.\(c\|so\)' -exec rm {} +
+
+if [[ "$OSTYPE" == "darwin"* ]]; then
+    find -E zipline tests -regex '.*\.(c|so)' -exec rm {} +
+else
+    find zipline tests -regex '.*\.\(c\|so\)' -exec rm {} +
+fi
 python setup.py build_ext --inplace