diff --git a/include/axolotl/cipher.hh b/include/axolotl/cipher.hh
index 93974fd7e554086c62d74f542fdf6b8ecc852ab8..5a077aa8e471b977a8078a94545516643855cc03 100644
--- a/include/axolotl/cipher.hh
+++ b/include/axolotl/cipher.hh
@@ -17,6 +17,7 @@
 #define AXOLOTL_CIPHER_HH_
 
 #include <cstdint>
+#include <cstddef>
 
 namespace axolotl {
 
diff --git a/src/message.cpp b/src/message.cpp
index 6ce8ca6573cf66718ce080704bee2a9832c318d7..7eea4c24ff91d97d38c36aae2a1246fb4078eb41 100644
--- a/src/message.cpp
+++ b/src/message.cpp
@@ -140,10 +140,10 @@ std::uint8_t const * skip_unknown(
 ) {
     if (pos != end) {
         uint8_t tag = *pos;
-        if (tag & 0x7 == 0) {
+        if ((tag & 0x7) == 0) {
             pos = varint_skip(pos, end);
             pos = varint_skip(pos, end);
-        } else if (tag & 0x7 == 2) {
+        } else if ((tag & 0x7) == 2) {
             pos = varint_skip(pos, end);
             std::uint8_t const * len_start = pos;
             pos = varint_skip(pos, end);
@@ -222,7 +222,7 @@ void axolotl::decode_message(
             reader.ciphertext, reader.ciphertext_length
         );
         if (unknown == pos) {
-            pos == skip_unknown(pos, end);
+            pos = skip_unknown(pos, end);
         }
         unknown = pos;
     }
@@ -305,7 +305,7 @@ void axolotl::decode_one_time_key_message(
             reader.message, reader.message_length
         );
         if (unknown == pos) {
-            pos == skip_unknown(pos, end);
+            pos = skip_unknown(pos, end);
         }
         unknown = pos;
     }