diff --git a/common/utils.c b/common/utils.c
index 1c6c5491b..bbf2864e7 100644
--- a/common/utils.c
+++ b/common/utils.c
@@ -200,7 +200,7 @@ int hex_decode(unsigned char *out,const unsigned char *in,int maxlen)
    int empty = TRUE;
 
    for(;len < maxlen;) {
-      if (*in > sizeof(hexval) || hexval[*in] == BAD)
+      if (*in >= sizeof(hexval) || hexval[*in] == BAD)
          break;
 
       if (empty) {