diff --git a/avrdude.conf.in b/avrdude.conf.in
index 47d12e35..42f390b3 100644
--- a/avrdude.conf.in
+++ b/avrdude.conf.in
@@ -11008,7 +11008,7 @@ part
 part
     id               = "usb646";
     desc             = "AT90USB646";
-    signature        = 0x1e 0x96 0x82; ?
+    signature        = 0x1e 0x96 0x82;
     has_jtag         = yes;
 #    stk500_devcode   = 0xB2;
 #    avr910_devcode   = 0x43;
@@ -11197,7 +11197,7 @@ part
 part
     id               = "usb647";
     desc             = "AT90USB647";
-    signature        = 0x1e 0x96 0x82; ?
+    signature        = 0x1e 0x96 0x82;
     has_jtag         = yes;
 #    stk500_devcode   = 0xB2;
 #    avr910_devcode   = 0x43;