diff --git a/subsys/jwt/jwt.c b/subsys/jwt/jwt.c
index b8a7a33143c..e5411fc6267 100644
--- a/subsys/jwt/jwt.c
+++ b/subsys/jwt/jwt.c
@@ -127,16 +127,6 @@ static int base64_append_bytes(const char *bytes, size_t len,
 	return 0;
 }
 
-struct jwt_header {
-	char *typ;
-	char *alg;
-};
-
-static struct json_obj_descr jwt_header_desc[] = {
-	JSON_OBJ_DESCR_PRIM(struct jwt_header, alg, JSON_TOK_STRING),
-	JSON_OBJ_DESCR_PRIM(struct jwt_header, typ, JSON_TOK_STRING),
-};
-
 struct jwt_payload {
 	int32_t exp;
 	int32_t iat;
@@ -152,25 +142,31 @@ static struct json_obj_descr jwt_payload_desc[] = {
 /*
  * Add the JWT header to the buffer.
  */
-static void jwt_add_header(struct jwt_builder *builder)
+static int jwt_add_header(struct jwt_builder *builder)
 {
-	static const struct jwt_header head = {
-		.typ = "JWT",
+	/*
+	 * Pre-computed JWT header
+	 * Use https://www.base64encode.org/ for update
+	 */
+	const char jwt_header[] =
 #ifdef CONFIG_JWT_SIGN_RSA
-		.alg = "RS256",
+		/* {"alg":"RS256","typ":"JWT"} */
+		"eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9";
 #endif
 #ifdef CONFIG_JWT_SIGN_ECDSA
-		.alg = "ES256",
+		/* {"alg":"ES256","typ":"JWT"} */
+		"eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9";
 #endif
-	};
+	int jwt_header_len = ARRAY_SIZE(jwt_header);
 
-	int res = json_obj_encode(jwt_header_desc, ARRAY_SIZE(jwt_header_desc),
-				  &head, base64_append_bytes, builder);
-	if (res != 0) {
-		/* Log an error here. */
-		return;
+	if (jwt_header_len > builder->len) {
+		builder->overflowed = true;
+		return -ENOSPC;
 	}
-	base64_flush(builder);
+	strcpy(builder->buf, jwt_header);
+	builder->buf += jwt_header_len - 1;
+	builder->len -= jwt_header_len - 1;
+	return 0;
 }
 
 int jwt_add_payload(struct jwt_builder *builder,
@@ -314,7 +310,5 @@ int jwt_init_builder(struct jwt_builder *builder,
 	builder->overflowed = false;
 	builder->pending = 0;
 
-	jwt_add_header(builder);
-
-	return 0;
+	return jwt_add_header(builder);
 }