diff --git a/windows.mk b/windows.mk
index 347c9a4..e05b93c 100644
--- a/windows.mk
+++ b/windows.mk
@@ -25,7 +25,7 @@
 # for the parts of OpenSSL used as well as that of the covered work.
 
 PACKAGE=yubico-piv-tool
-OPENSSLVERSION=1.0.1m
+OPENSSLVERSION=1.0.1o
 
 all: usage 32bit 64bit