diff --git a/ChangeLog b/ChangeLog
index 68efd800..f3560c66 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2005-02-07  Stephen Hemminger  <shemminger@dxpl.pdx.osdl.net>
+
+	* Validate classid is not too large to cause loss of bits.
+
 2005-02-07 Jean-Marc Ranger <jmranger@sympatico.ca>
 
 	* need to call getline() with null for first usage
diff --git a/tc/tc_util.c b/tc/tc_util.c
index 0dc76c03..a6413e66 100644
--- a/tc/tc_util.c
+++ b/tc/tc_util.c
@@ -61,11 +61,15 @@ int get_tc_classid(__u32 *h, const char *str)
 			return -1;
 	}
 	if (*p == ':') {
+		if (maj >= (1<<16))
+			return -1;
 		maj <<= 16;
 		str = p+1;
 		min = strtoul(str, &p, 16);
 		if (*p != 0)
 			return -1;
+		if (min >= (1<<16))
+			return -1;
 		maj |= min;
 	} else if (*p != 0)
 		return -1;