diff --git a/tools/polyprep/requirements.txt b/tools/polyprep/requirements.txt
index b6d94996..d5cc80ce 100644
--- a/tools/polyprep/requirements.txt
+++ b/tools/polyprep/requirements.txt
@@ -1,3 +1,3 @@
-Fiona==1.9.4.post1
+fiona>=1.10b2
 Rtree==1.0.1
 shapely==2.0.1