diff --git a/bootloader/signatures.c b/bootloader/signatures.c
index 37e5f67b8..ec6ca3af6 100644
--- a/bootloader/signatures.c
+++ b/bootloader/signatures.c
@@ -119,7 +119,11 @@ bool firmware_present_new(void)
 {
 	const image_header *hdr = (const image_header *)FLASH_PTR(FLASH_FWHEADER_START);
 	if (hdr->magic != FIRMWARE_MAGIC_NEW) return false;
-	if (hdr->hdrlen != FLASH_FWHEADER_LEN) return false;
+	// we need to ignore hdrlen for now
+	// because we keep reset_handler ptr there
+	// for compatibility with older bootloaders
+	// after this is no longer necessary, let's uncomment the line below:
+	// if (hdr->hdrlen != FLASH_FWHEADER_LEN) return false;
 	if (hdr->codelen > FLASH_APP_LEN) return false;
 	if (hdr->codelen < 4096) return false;
 
diff --git a/firmware/bl_check.c b/firmware/bl_check.c
index 50c8ac488..04cd8644b 100644
--- a/firmware/bl_check.c
+++ b/firmware/bl_check.c
@@ -26,7 +26,7 @@
 #include "gettext.h"
 #include "util.h"
 
-int known_bootloader(int r, const uint8_t *hash) {
+static int known_bootloader(int r, const uint8_t *hash) {
 	if (r != 32) return 0;
 	if (0 == memcmp(hash, "\xbf\x72\xe2\x5e\x2c\x2f\xc1\xba\x57\x04\x50\xfa\xdf\xb6\x6f\xaa\x5a\x71\x6d\xcd\xc0\x33\x35\x88\x55\x7b\x77\x54\x0a\xb8\x7e\x98", 32)) return 1;  // 1.2.0a
 	if (0 == memcmp(hash, "\x77\xb8\xe2\xf2\x5f\xaa\x8e\x8c\x7d\x9f\x5b\x32\x3b\x27\xce\x05\x6c\xa3\xdb\xc2\x3f\x56\xc3\x7e\xe3\x3f\x97\x7c\xa6\xeb\x4d\x3e", 32)) return 1;  // 1.2.0b
@@ -44,7 +44,7 @@ int known_bootloader(int r, const uint8_t *hash) {
 	if (0 == memcmp(hash, "\x3e\xc4\xbd\xd5\x77\xea\x0c\x36\xc7\xba\xb7\xb9\xa3\x5b\x87\x17\xb3\xf1\xfc\x2f\x80\x9e\x69\x0c\x8a\xbe\x5b\x05\xfb\xc2\x43\xc6", 32)) return 1;  // 1.6.0 shipped with fw 1.7.0
 	if (0 == memcmp(hash, "\x8e\x83\x02\x3f\x0d\x4f\x82\x4f\x64\x71\x20\x75\x2b\x6c\x71\x6f\x55\xd7\x95\x70\x66\x8f\xd4\x90\x65\xd5\xb7\x97\x6e\x7a\x6e\x19", 32)) return 1;  // 1.6.0 shipped with fw 1.7.1 and 1.7.2
 	if (0 == memcmp(hash, "\xa2\x36\x6e\x77\xde\x8e\xfd\xfd\xc9\x99\xf4\x72\x20\xc0\x16\xe3\x3f\x6d\x24\x24\xe2\x45\x90\x79\x11\x7a\x90\xb3\xa8\x88\xba\xdd", 32)) return 1;  // 1.6.1 shipped with fw 1.7.3
-	if (0 == memcmp(hash, "\xaf\x19\x47\x7b\xf1\x4c\x33\x81\x34\x78\xd3\x29\x46\x58\x3b\x5d\xcf\xb2\x13\xc5\xba\x92\x81\x1e\x46\x50\x8e\xd0\x14\xb7\xa6\x14", 32)) return 1;  // 1.8.0 shipped with fw 1.8.0
+	if (0 == memcmp(hash, "\xd2\xe7\x5b\x31\xaa\x66\x88\x74\x90\x3a\x30\x9e\x65\xc9\x4d\x0b\x36\x6b\x1d\xc8\xca\x8d\xda\x37\xba\x6f\x16\x6e\x50\x82\xae\xda", 32)) return 1;  // 1.8.0 shipped with fw 1.8.0
 	return 0;
 }
 
diff --git a/firmware/header.S b/firmware/header.S
index 9333fb238..46e4aa375 100644
--- a/firmware/header.S
+++ b/firmware/header.S
@@ -9,7 +9,7 @@
 
 g_header:
     .byte 'T','R','Z','F'            // magic
-    .word g_header_end - g_header    // hdrlen
+    .word reset_handler              // reset handler,  replace later with : .word g_header_end - g_header    // hdrlen
     .word 0                          // expiry
     .word _codelen                   // codelen
     .byte VERSION_MAJOR              // vmajor
diff --git a/startup.s b/startup.s
index 59a87e1af..ce75ba1a7 100644
--- a/startup.s
+++ b/startup.s
@@ -19,6 +19,16 @@ memset_reg:
   .global reset_handler
   .type reset_handler, STT_FUNC
 reset_handler:
+// we need to perform this in case an old bootloader
+// is starting the new firmware, these will be set incorrectly
+  ldr r0, =0xE000ED08  // r0 = VTOR address
+  ldr r1, =0x08010400  // r1 = FLASH_APP_START
+  str r1, [r0]         // assign
+  ldr r0, =_stack      // r0 = stack pointer
+  msr msp, r0          // set stack pointer
+  dsb
+  isb
+
   ldr r0, =_ram_start // r0 - point to beginning of SRAM
   ldr r1, =_ram_end   // r1 - point to byte after the end of SRAM
   ldr r2, =0          // r2 - the byte-sized value to be written