diff --git a/boot/bootutil/include/bootutil/image.h b/boot/bootutil/include/bootutil/image.h
index a1541b8..12819bc 100644
--- a/boot/bootutil/include/bootutil/image.h
+++ b/boot/bootutil/include/bootutil/image.h
@@ -52,10 +52,10 @@
 /*
  * Image trailer TLV types.
  */
-#define IMAGE_TLV_SHA256            1	/* SHA256 of image hdr and body */
-#define IMAGE_TLV_RSA2048           2	/* RSA2048 of hash output */
-#define IMAGE_TLV_ECDSA224          3   /* ECDSA of hash output */
-#define IMAGE_TLV_ECDSA256          4   /* ECDSA of hash output */
+#define IMAGE_TLV_SHA256            0x10   /* SHA256 of image hdr and body */
+#define IMAGE_TLV_RSA2048           0x20   /* RSA2048 of hash output */
+#define IMAGE_TLV_ECDSA224          0x21   /* ECDSA of hash output */
+#define IMAGE_TLV_ECDSA256          0x22   /* ECDSA of hash output */
 
 struct image_version {
     uint8_t iv_major;
diff --git a/doc/design.txt b/doc/design.txt
index 8894304..409147f 100644
--- a/doc/design.txt
+++ b/doc/design.txt
@@ -90,10 +90,10 @@
 /*
  * Image trailer TLV types.
  */
-#define IMAGE_TLV_SHA256            1   /* SHA256 of image hdr and body */
-#define IMAGE_TLV_RSA2048           2   /* RSA2048 of hash output */
-#define IMAGE_TLV_ECDSA224          3   /* ECDSA of hash output */
-#define IMAGE_TLV_ECDSA256          4   /* ECDSA of hash output */
+#define IMAGE_TLV_SHA256            0x10   /* SHA256 of image hdr and body */
+#define IMAGE_TLV_RSA2048           0x20   /* RSA2048 of hash output */
+#define IMAGE_TLV_ECDSA224          0x21   /* ECDSA of hash output */
+#define IMAGE_TLV_ECDSA256          0x22   /* ECDSA of hash output */
 
 Optional type-length-value records (TLVs) containing image metadata are placed
 after the end of the image.
diff --git a/scripts/imgtool/image.py b/scripts/imgtool/image.py
index 4cb6662..cd031be 100644
--- a/scripts/imgtool/image.py
+++ b/scripts/imgtool/image.py
@@ -20,10 +20,10 @@
         'PKCS1_PSS_RSA2048_SHA256': 0x0000040, }
 
 TLV_VALUES = {
-        'SHA256': 1,
-        'RSA2048': 2,
-        'ECDSA224': 3,
-        'ECDSA256': 4, }
+        'SHA256': 0x10,
+        'RSA2048': 0x20,
+        'ECDSA224': 0x21,
+        'ECDSA256': 0x22, }
 
 TLV_HEADER_SIZE = 4
 
diff --git a/sim/src/tlv.rs b/sim/src/tlv.rs
index 59bdf2c..f4c88b0 100644
--- a/sim/src/tlv.rs
+++ b/sim/src/tlv.rs
@@ -29,10 +29,10 @@
 #[derive(Copy, Clone, PartialEq, Eq)]
 #[allow(dead_code)] // TODO: For now
 pub enum TlvKinds {
-    SHA256 = 1,
-    RSA2048 = 2,
-    ECDSA224 = 3,
-    ECDSA256 = 4,
+    SHA256 = 0x10,
+    RSA2048 = 0x20,
+    ECDSA224 = 0x21,
+    ECDSA256 = 0x22,
 }
 
 pub struct TlvGen {