diff --git a/build_shared_library.py b/build_shared_library.py
index ed8f93fb4d544b150df1985de7592a5fe6ac2f62..911c7b30be020886fd05b3c054f460626381cf36 100755
--- a/build_shared_library.py
+++ b/build_shared_library.py
@@ -23,7 +23,7 @@ if not os.path.exists("build"):
 
 source_files = glob.glob("src/*.cpp")
 
-compile_args = "g++ -O3 -Iinclude -Ilib --std=c++11 --shared -fPIC".split()
+compile_args = "g++ -Wall -O3 -Iinclude -Ilib --std=c++11 --shared -fPIC".split()
 compile_args += source_files
 compile_args += sys.argv[1:]
 
diff --git a/include/olm/base64.hh b/include/olm/base64.hh
index da4641deccfdca73eb715c58892f169390a93e1f..dfdccd02968e879712493ac501cc1c85a24c41cc 100644
--- a/include/olm/base64.hh
+++ b/include/olm/base64.hh
@@ -23,11 +23,9 @@ namespace olm {
 /**
  * The number of bytes of unpadded base64 needed to encode a length of input.
  */
-static std::size_t encode_base64_length(
+std::size_t encode_base64_length(
     std::size_t input_length
-) {
-    return 4 * ((input_length + 2) / 3) + (input_length + 2) % 3 - 2;
-}
+);
 
 /**
  * Encode the raw input as unpadded base64.
diff --git a/include/olm/pickle.hh b/include/olm/pickle.hh
index 27f1f26e82a62a44c10fb021c4740d9f6330bc55..13e6b01535c9b66ca17496ef8f969226dfc1e35e 100644
--- a/include/olm/pickle.hh
+++ b/include/olm/pickle.hh
@@ -23,58 +23,38 @@
 
 namespace olm {
 
-static std::size_t pickle_length(
+inline std::size_t pickle_length(
     const std::uint32_t & value
 ) {
     return 4;
 }
 
-
-static std::uint8_t * pickle(
+std::uint8_t * pickle(
     std::uint8_t * pos,
     std::uint32_t value
-) {
-    pos += 4;
-    for (unsigned i = 4; i--;) { *(--pos) = value; value >>= 8; }
-    return pos + 4;
-}
-
+);
 
-static std::uint8_t const * unpickle(
+std::uint8_t const * unpickle(
     std::uint8_t const * pos, std::uint8_t const * end,
     std::uint32_t & value
-) {
-    value = 0;
-    if (end - pos < 4) return end;
-    for (unsigned i = 4; i--;) { value <<= 8; value |= *(pos++); }
-    return pos;
-}
+);
+
 
-static std::size_t pickle_length(
+inline std::size_t pickle_length(
     const bool & value
 ) {
     return 1;
 }
 
-
-static std::uint8_t * pickle(
+std::uint8_t * pickle(
     std::uint8_t * pos,
     bool value
-) {
-    *(pos++) = value ? 1 : 0;
-    return pos;
-}
-
+);
 
-static std::uint8_t const * unpickle(
+std::uint8_t const * unpickle(
     std::uint8_t const * pos, std::uint8_t const * end,
     bool & value
-) {
-    if (pos == end) return end;
-    value = *(pos++);
-    return pos;
-}
-
+);
 
 
 template<typename T, std::size_t max_size>
@@ -117,23 +97,15 @@ std::uint8_t const * unpickle(
 }
 
 
-static std::uint8_t * pickle_bytes(
+std::uint8_t * pickle_bytes(
     std::uint8_t * pos,
     std::uint8_t const * bytes, std::size_t bytes_length
-) {
-    std::memcpy(pos, bytes, bytes_length);
-    return pos + bytes_length;
-}
-
+);
 
-static std::uint8_t const * unpickle_bytes(
+std::uint8_t const * unpickle_bytes(
     std::uint8_t const * pos, std::uint8_t const * end,
     std::uint8_t * bytes, std::size_t bytes_length
-) {
-    if (end - pos < bytes_length) return end;
-    std::memcpy(bytes, pos, bytes_length);
-    return pos + bytes_length;
-}
+);
 
 
 std::size_t pickle_length(
diff --git a/include/olm/session.hh b/include/olm/session.hh
index b21b0aa9dda97076ed584bb49d668d48c63dec8d..829f27191cc7a86da9c08dc1a273a80b76b722bf 100644
--- a/include/olm/session.hh
+++ b/include/olm/session.hh
@@ -19,7 +19,7 @@
 
 namespace olm {
 
-class Account;
+struct Account;
 
 enum struct MessageType {
     PRE_KEY = 0,
diff --git a/include/olm/utility.hh b/include/olm/utility.hh
index 5329a594957cbc79e8f5d0b4265b1ac1603b110b..1e77675c036a0319ff40e225cb5efb678987dabb 100644
--- a/include/olm/utility.hh
+++ b/include/olm/utility.hh
@@ -23,7 +23,7 @@
 
 namespace olm {
 
-class Ed25519PublicKey;
+struct Ed25519PublicKey;
 
 struct Utility {
 
diff --git a/javascript/build.py b/javascript/build.py
index fb58a2c843c53c2a51110939ecbaa4abf754f4cd..f253acb3648411b4182ff5a3d686ac95ead3886c 100755
--- a/javascript/build.py
+++ b/javascript/build.py
@@ -45,6 +45,7 @@ optimize_opts = os.environ.get("OPTIMIZE_FLAGS", "-O3")
 
 compile_args = [emcc]
 compile_args += optimize_opts.split()
+compile_args += ["-Wall"]
 compile_args += """
     -Iinclude
     -Ilib
diff --git a/src/base64.cpp b/src/base64.cpp
index bf8492e04dd4b6261956f83703d051b30d542f45..66f512ba7836f2ff902943550863b1e5c3fa9be0 100644
--- a/src/base64.cpp
+++ b/src/base64.cpp
@@ -45,6 +45,12 @@ static const std::uint8_t DECODE_BASE64[128] = {
 } // namespace
 
 
+std::size_t olm::encode_base64_length(
+    std::size_t input_length
+) {
+    return 4 * ((input_length + 2) / 3) + (input_length + 2) % 3 - 2;
+}
+
 std::uint8_t * olm::encode_base64(
     std::uint8_t const * input, std::size_t input_length,
     std::uint8_t * output
diff --git a/src/message.cpp b/src/message.cpp
index 30abd9cdb1286a51e4b77bd15e65ce7442341467..23ec82360e0302fa1d08b1d691a99d524bf38896 100644
--- a/src/message.cpp
+++ b/src/message.cpp
@@ -136,7 +136,7 @@ static std::uint8_t const * decode(
         std::uint8_t const * len_start = pos;
         pos = varint_skip(pos, end);
         std::size_t len = varint_decode<std::size_t>(len_start, pos);
-        if (len > end - pos) return end;
+        if (len + pos > end) return end;
         value = pos;
         value_length = len;
         pos += len;
@@ -157,7 +157,7 @@ static std::uint8_t const * skip_unknown(
             std::uint8_t const * len_start = pos;
             pos = varint_skip(pos, end);
             std::size_t len = varint_decode<std::size_t>(len_start, pos);
-            if (len > end - pos) return end;
+            if (len + pos > end) return end;
             pos += len;
         } else {
             return end;
diff --git a/src/pickle.cpp b/src/pickle.cpp
index 25580d25240aaa6eee61053c37c95b648fbb69b5..00f7cd46119034c5ec6912b3d7daacf8d7e11937 100644
--- a/src/pickle.cpp
+++ b/src/pickle.cpp
@@ -14,6 +14,60 @@
  */
 #include "olm/pickle.hh"
 
+std::uint8_t * olm::pickle(
+    std::uint8_t * pos,
+    std::uint32_t value
+) {
+    pos += 4;
+    for (unsigned i = 4; i--;) { *(--pos) = value; value >>= 8; }
+    return pos + 4;
+}
+
+
+std::uint8_t const * olm::unpickle(
+    std::uint8_t const * pos, std::uint8_t const * end,
+    std::uint32_t & value
+) {
+    value = 0;
+    if (end < pos + 4) return end;
+    for (unsigned i = 4; i--;) { value <<= 8; value |= *(pos++); }
+    return pos;
+}
+
+std::uint8_t * olm::pickle(
+    std::uint8_t * pos,
+    bool value
+) {
+    *(pos++) = value ? 1 : 0;
+    return pos;
+}
+
+std::uint8_t const * olm::unpickle(
+    std::uint8_t const * pos, std::uint8_t const * end,
+    bool & value
+) {
+    if (pos == end) return end;
+    value = *(pos++);
+    return pos;
+}
+
+std::uint8_t * olm::pickle_bytes(
+    std::uint8_t * pos,
+    std::uint8_t const * bytes, std::size_t bytes_length
+) {
+    std::memcpy(pos, bytes, bytes_length);
+    return pos + bytes_length;
+}
+
+std::uint8_t const * olm::unpickle_bytes(
+    std::uint8_t const * pos, std::uint8_t const * end,
+    std::uint8_t * bytes, std::size_t bytes_length
+) {
+    if (end < pos + bytes_length) return end;
+    std::memcpy(bytes, pos, bytes_length);
+    return pos + bytes_length;
+}
+
 
 std::size_t olm::pickle_length(
     const olm::Curve25519PublicKey & value