diff --git a/src/bacnet/bacdcode.c b/src/bacnet/bacdcode.c
index 25af2946..f0ba3853 100644
--- a/src/bacnet/bacdcode.c
+++ b/src/bacnet/bacdcode.c
@@ -2487,6 +2487,8 @@ int bacnet_character_string_decode(
                 string_value = (const char *)&apdu[1];
                 (void)characterstring_init(
                     char_string, encoding, string_value, len_value - 1);
+            } else {
+                (void)characterstring_init(char_string, encoding, NULL, 0);
             }
             len = (int)len_value;
         }