1 files changed, 1 insertions, 0 deletions
diff --git a/hash.c b/hash.c
index 3ef6668f5f..c4a2c0f634 100644
--- a/hash.c
+++ b/hash.c
@@ -3034,6 +3034,7 @@ ruby_unsetenv(const char *name)
  *
  * Sets the environment variable +name+ to +value+.  If the value given is
  * +nil+ the environment variable is deleted.
+ * +name+ must be a string.
  *
  */
 static VALUE