diff --git a/stream/mts/psi/op.go b/stream/mts/psi/op.go
index 55f9df8d..331019b7 100644
--- a/stream/mts/psi/op.go
+++ b/stream/mts/psi/op.go
@@ -105,10 +105,13 @@ func LocationFrom(p []byte) (g string, err error) {
 
 // LocationStrBytes take a string of location data and converts to a 32 byte slice -
 // easy update of slice representation of a pmt with location descriptor
-func LocationStrBytes(l string) (out []byte) {
-	out = make([]byte, locationDataSize)
-	copy(out, []byte(l))
-	return
+func LocationStrBytes(s string) []byte {
+	if len(s) != locationDataSize {
+		panic("Location string not the right size")
+	}
+	var b [locationDataSize]byte
+	copy(b[:], s)
+	return b[:]
 }
 
 // UpdateLocation takes a byte slice representation of a psi-pmt containing a location