diff --git a/libsrc/telestrat/lseek.s b/libsrc/telestrat/lseek.s
index 11d1fad33..e94cba46c 100644
--- a/libsrc/telestrat/lseek.s
+++ b/libsrc/telestrat/lseek.s
@@ -35,5 +35,12 @@
         ldy     tmp3
         ldx     tmp1          ; Get whence
         BRK_TELEMON XFSEEK
+        ; A & X contains position (from 0 to 15 bits)
+        ; RES (2 bytes) contains position (from 16 to 31 bits)
+        ; Returns long
+        ldy     RES+1
+        sty     sreg+1
+        ldy     RES
+        sty     sreg
         rts
 .endproc