diff --git a/src/kits/mail/Jamfile b/src/kits/mail/Jamfile
index 442c18bd04..07f2f4032e 100644
--- a/src/kits/mail/Jamfile
+++ b/src/kits/mail/Jamfile
@@ -19,7 +19,7 @@ local sources =
 	des.c
 	FileConfigView.cpp
 	HaikuMailFormatFilter.cpp
-	mail_encoding.c
+	mail_encoding.cpp
 	mail_util.cpp
 	MailAttachment.cpp
 	MailComponent.cpp
diff --git a/src/kits/mail/mail_encoding.c b/src/kits/mail/mail_encoding.cpp
similarity index 100%
rename from src/kits/mail/mail_encoding.c
rename to src/kits/mail/mail_encoding.cpp