diff --git a/src/evalfunc.c b/src/evalfunc.c
index da8f845..690b921 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -9223,9 +9223,9 @@
     name = tv_get_string_buf(&argvars[0], namebuf);
     if (argvars[1].v_type == VAR_SPECIAL
 				      && argvars[1].vval.v_number == VVAL_NULL)
-	vim_unsetenv(name);
+	vim_unsetenv_ext(name);
     else
-	vim_setenv(name, tv_get_string_buf(&argvars[1], valbuf));
+	vim_setenv_ext(name, tv_get_string_buf(&argvars[1], valbuf));
 }
 
 /*