diff --git a/src/pch.c b/src/pch.c

index e92bc64..a500ad9 100644

--- a/src/pch.c

+++ b/src/pch.c

@@ -2122,7 +2122,7 @@ pch_swap (void)

     }

     if (p_efake >= 0) {			/* fix non-freeable ptr range */

 	if (p_efake <= i)

-	    n = p_end - i + 1;

+	    n = p_end - p_ptrn_lines;

 	else

 	    n = -i;

 	p_efake += n;