diff --git a/requirements-frozen.txt b/requirements-frozen.txt
index c5f19bd..8b5f232 100644
--- a/requirements-frozen.txt
+++ b/requirements-frozen.txt
@@ -1,4 +1,4 @@
-antlib==1.1b0.post0
+antlib==1.1b0.post0 ; sys_platform == 'win32'
 Click==7.0
 crcmod==1.7
 ecdsa==0.13.3