diff --git a/gpgmeplug/gpgme-openpgp.c b/gpgmeplug/gpgme-openpgp.c
index 042a11dc..56908e1b 100644
--- a/gpgmeplug/gpgme-openpgp.c
+++ b/gpgmeplug/gpgme-openpgp.c
@@ -16,7 +16,7 @@
 #define GPGMEPLUG_SIGN_FLAT_PREFIX       ""
 #define GPGMEPLUG_SIGN_FLAT_SEPARATOR    ""
 #define GPGMEPLUG_SIGN_FLAT_POSTFIX      ""
-#define __GPGMEPLUG_SIGNATURE_CODE_IS_BINARY true
+#define __GPGMEPLUG_SIGNATURE_CODE_IS_BINARY false
 
 #define GPGMEPLUG_ENC_INCLUDE_CLEARTEXT  false
 #define GPGMEPLUG_ENC_MAKE_MIME_OBJECT   true