diff --git a/src/ec/it5570e/signature.c b/src/ec/it5570e/signature.c
index 7b9bcf3..477da26 100644
--- a/src/ec/it5570e/signature.c
+++ b/src/ec/it5570e/signature.c
@@ -4,20 +4,14 @@
 
 #if EC_ESPI
 // eSPI signature (byte 7 = 0xA4)
-static __code char __at(0x40) SIGNATURE[32] = {
+static __code const unsigned char __at(0x40) SIGNATURE[16] = {
     0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA4, 0x95,
     0x85, 0x12, 0x5A, 0x5A, 0xAA, 0x00, 0x55, 0x55,
-
-    0x49, 0x54, 0x45, 0x20, 0x54, 0x65, 0x63, 0x68,
-    0x2E, 0x20, 0x49, 0x6E, 0x63, 0x2E, 0x20, 0x20
 };
 #else // EC_ESPI
 // LPC signature (byte 7 = 0xA5)
-static __code char __at(0x40) SIGNATURE[32] = {
+static __code const unsigned char __at(0x40) SIGNATURE[16] = {
     0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0x94,
     0x85, 0x12, 0x5A, 0x5A, 0xAA, 0x00, 0x55, 0x55,
-
-    0x49, 0x54, 0x45, 0x20, 0x54, 0x65, 0x63, 0x68,
-    0x2E, 0x20, 0x49, 0x6E, 0x63, 0x2E, 0x20, 0x20
 };
 #endif // EC_ESPI
diff --git a/src/ec/it8587e/signature.c b/src/ec/it8587e/signature.c
index 274d311..44faaf8 100644
--- a/src/ec/it8587e/signature.c
+++ b/src/ec/it8587e/signature.c
@@ -1,9 +1,6 @@
 // SPDX-License-Identifier: GPL-3.0-only
 
-static __code char __at(0x40) SIGNATURE[32] = {
+static __code const unsigned char __at(0x40) SIGNATURE[16] = {
     0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0x94,
     0x85, 0x12, 0x5A, 0x5A, 0xAA, 0x00, 0x55, 0x55,
-
-    0x49, 0x54, 0x45, 0x20, 0x54, 0x65, 0x63, 0x68,
-    0x2E, 0x20, 0x49, 0x6E, 0x63, 0x2E, 0x20, 0x20
 };