diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 8fda3b3..885e3b4 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -1504,9 +1504,11 @@
 		if ($line =~ /^diff --git.*?(\S+)$/) {
 			$realfile = $1;
 			$realfile =~ s@^([^/]*)/@@;
+			$in_commit_log = 0;
 		} elsif ($line =~ /^\+\+\+\s+(\S+)/) {
 			$realfile = $1;
 			$realfile =~ s@^([^/]*)/@@;
+			$in_commit_log = 0;
 
 			$p1_prefix = $1;
 			if (!$file && $tree && $p1_prefix ne '' &&
@@ -1546,7 +1548,8 @@
 		}
 
 # Check signature styles
-		if ($line =~ /^(\s*)($signature_tags)(\s*)(.*)/) {
+		if (!$in_header_lines &&
+		    $line =~ /^(\s*)($signature_tags)(\s*)(.*)/) {
 			my $space_before = $1;
 			my $sign_off = $2;
 			my $space_after = $3;
@@ -1623,7 +1626,7 @@
 # Check if it's the start of a commit log
 # (not a header line and we haven't seen the patch filename)
 		if ($in_header_lines && $realfile =~ /^$/ &&
-		    $rawline !~ /^(commit\b|from\b|\w+:).+$/i) {
+		    $rawline !~ /^(commit\b|from\b|[\w-]+:).+$/i) {
 			$in_header_lines = 0;
 			$in_commit_log = 1;
 		}