diff --git a/Tools/ardupilotwaf/embed.py b/Tools/ardupilotwaf/embed.py
index 06104eec20..723b4f243c 100644
--- a/Tools/ardupilotwaf/embed.py
+++ b/Tools/ardupilotwaf/embed.py
@@ -17,8 +17,7 @@ def embed_file(out, f, idx, embedded_name, uncompressed):
     try:
         contents = open(f,'rb').read()
     except Exception:
-        print("Failed to embed %s" % f)
-        return False
+        raise Exception("Failed to embed %s" % f)
 
     pad = 0
     if embedded_name.endswith("bootloader.bin"):
@@ -34,6 +33,7 @@ def embed_file(out, f, idx, embedded_name, uncompressed):
                     contents += bytes(chr(0xff))
             print("Padded %u bytes for %s to %u" % (pad, embedded_name, len(contents)))
 
+    crc = crc32(contents)
     write_encode(out, 'static const uint8_t ap_romfs_%u[] = {' % idx)
 
     compressed = tempfile.NamedTemporaryFile()
@@ -60,7 +60,7 @@ def embed_file(out, f, idx, embedded_name, uncompressed):
     for c in b:
         write_encode(out, '%u,' % c)
     write_encode(out, '};\n\n');
-    return True
+    return crc
 
 def crc32(bytes, crc=0):
     '''crc32 equivalent to crc32_small() from AP_Math/crc.cpp'''
@@ -80,10 +80,13 @@ def create_embedded_h(filename, files, uncompressed=False):
 
     # remove duplicates and sort
     files = sorted(list(set(files)))
-
+    crc = {}
     for i in range(len(files)):
         (name, filename) = files[i]
-        if not embed_file(out, filename, i, name, uncompressed):
+        try:
+            crc[filename] = embed_file(out, filename, i, name, uncompressed)
+        except Exception as e:
+            print(e)
             return False
 
     write_encode(out, '''const AP_ROMFS::embedded_file AP_ROMFS::files[] = {\n''')
@@ -95,8 +98,7 @@ def create_embedded_h(filename, files, uncompressed=False):
         else:
             ustr = ''
         print("Embedding file %s:%s%s" % (name, filename, ustr))
-        crc = crc32(bytearray(open(filename,'rb').read()))
-        write_encode(out, '{ "%s", sizeof(ap_romfs_%u), 0x%08x, ap_romfs_%u },\n' % (name, i, crc, i))
+        write_encode(out, '{ "%s", sizeof(ap_romfs_%u), 0x%08x, ap_romfs_%u },\n' % (name, i, crc[filename], i))
     write_encode(out, '};\n')
     out.close()
     return True