diff --git a/src/if_tcl.c b/src/if_tcl.c
index d3d4639..eab321b 100644
--- a/src/if_tcl.c
+++ b/src/if_tcl.c
@@ -2012,7 +2012,8 @@
 #if (TCL_MAJOR_VERSION == 8 && TCL_MINOR_VERSION >= 5) || TCL_MAJOR_VERSION > 8
 	    || Tcl_LimitExceeded(tclinfo.interp)
 #endif
-	    || curbuf != was_curbuf)
+	    || curbuf != was_curbuf
+	    || (linenr_T)rs > curbuf->b_ml.ml_line_count)
 	    break;
 	line = (char *)Tcl_GetVar(tclinfo.interp, var_line, 0);
 	if (line)