diff --git a/git-send-email.perl b/git-send-email.perl
index 6bedf745e7..819f87e8df 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -522,12 +522,12 @@ my %parse_alias = (
 
 		# warn on lines that contain quotes
 		elsif (/"/) {
-			print STDERR "sendmail alias with quotes is not supported: $_\n";
+			print STDERR "warning: sendmail alias with quotes is not supported: $_\n";
 		}
 
 		# warn on lines that continue
 		elsif (/^\s|\\$/) {
-			print STDERR "sendmail continuation line is not supported: $_\n";
+			print STDERR "warning: sendmail continuation line is not supported: $_\n";
 		}
 
 		# recognize lines that look like an alias
@@ -538,7 +538,7 @@ my %parse_alias = (
 
 		# warn on lines that are not recognized
 		else {
-			print STDERR "sendmail line is not recognized: $_\n";
+			print STDERR "warning: sendmail line is not recognized: $_\n";
 		}}},
 
 	gnus => sub { my $fh = shift; while (<$fh>) {