diff --git a/lib/wsprd/wsprsim_utils.c b/lib/wsprd/wsprsim_utils.c
index be3fd6ce7..dc5524ad9 100644
--- a/lib/wsprd/wsprsim_utils.c
+++ b/lib/wsprd/wsprsim_utils.c
@@ -184,7 +184,7 @@ int get_wspr_channel_symbols(char* message, unsigned char* symbols) {
     // Use the presence and/or absence of "<" and "/" to decide what
     // type of message. No sanity checks! Beware!
     
-    if( (i1>3) & (i1<6) & (i2==mlen) & (i3==mlen) ) {
+    if( (i1>3) & (i1<7) & (i2==mlen) & (i3==mlen) ) {
         // Type 1 message: K9AN EN50 33
         //                 xxnxxxx xxnn nn
         const char s[2]=" ";