diff --git a/lib/diff.tcl b/lib/diff.tcl
index ec4405567a..30d9a79776 100644
--- a/lib/diff.tcl
+++ b/lib/diff.tcl
@@ -764,8 +764,15 @@ proc apply_range_or_line {x y} {
 				# context line
 				set ln [$ui_diff get $i_l $next_l]
 				set patch "$patch$pre_context$ln"
-				set n [expr $n+1]
-				set m [expr $m+1]
+				# Skip the "\ No newline at end of
+				# file". Depending on the locale setting
+				# we don't know what this line looks
+				# like exactly. The only thing we do
+				# know is that it starts with "\ "
+				if {![string match {\\ *} $ln]} {
+					set n [expr $n+1]
+					set m [expr $m+1]
+				}
 				set pre_context {}
 			} elseif {$c1 eq $to_context} {
 				# turn change line into context line