diff --git a/pack_template.h b/pack_template.h
index 70064783..e12a7a0e 100644
--- a/pack_template.h
+++ b/pack_template.h
@@ -713,7 +713,7 @@ msgpack_pack_inline_func(_false)(msgpack_pack_user x)
 msgpack_pack_inline_func(_array)(msgpack_pack_user x, size_t n)
 {
 	if(n < 16) {
-		unsigned char d = 0x90 | n;
+		unsigned char d = 0x90 | (uint8_t)n;
 		msgpack_pack_append_buffer(x, &d, 1);
 	} else if(n < 65536) {
 		unsigned char buf[3];
@@ -734,7 +734,7 @@ msgpack_pack_inline_func(_array)(msgpack_pack_user x, size_t n)
 msgpack_pack_inline_func(_map)(msgpack_pack_user x, size_t n)
 {
 	if(n < 16) {
-		unsigned char d = 0x80 | n;
+		unsigned char d = 0x80 | (uint8_t)n;
 		msgpack_pack_append_buffer(x, &TAKE8_8(d), 1);
 	} else if(n < 65536) {
 		unsigned char buf[3];
diff --git a/unpack_template.h b/unpack_template.h
index c4816e4a..60611c6c 100644
--- a/unpack_template.h
+++ b/unpack_template.h
@@ -232,7 +232,7 @@ msgpack_unpack_func(int, _execute)(msgpack_unpack_struct(_context)* ctx, const c
 				case 0xdd:  // array 32
 				case 0xde:  // map 16
 				case 0xdf:  // map 32
-					again_fixed_trail(NEXT_CS(p), 2 << (((unsigned int)*p) & 0x01));
+					again_fixed_trail(NEXT_CS(p), 2u << (((unsigned int)*p) & 0x01));
 				default:
 					goto _failed;
 				}
@@ -397,7 +397,7 @@ _end:
 	ctx->cs = cs;
 	ctx->trail = trail;
 	ctx->top = top;
-	*off = p - (const unsigned char*)data;
+	*off = (size_t)(p - (const unsigned char*)data);
 
 	return ret;
 }