diff --git a/Android.mk b/Android.mk
index 7fc7769bb6c14e411ab9b963200cbfa6e0de1d25..98ea8475e47486219a10a1417e6964c974401860 100644
--- a/Android.mk
+++ b/Android.mk
@@ -177,7 +177,7 @@ ifneq (,$(filter address,$(SANITIZE_TARGET)))
 endif
 
 # Library extension for host-side tests
-ifeq ($(HOSTOS),darwin)
+ifeq ($(HOST_OS),darwin)
 SHAREDLIB_EXT=dylib
 else
 SHAREDLIB_EXT=so