diff --git a/code/errno.c b/code/errno.c
index cdb2993..999fd65 100644
--- a/code/errno.c
+++ b/code/errno.c
@@ -1,4 +1,4 @@
 
 #include <errno.h>
 
-int errno;
+_Thread_local int errno;
diff --git a/inc/errno.h b/inc/errno.h
index 2f846a9..afa3fc7 100644
--- a/inc/errno.h
+++ b/inc/errno.h
@@ -6,4 +6,4 @@
 #define ERANGE 3
 
 // TODO: make it thread-local
-extern int errno;
+extern _Thread_local int errno;