diff --git a/Makefile b/Makefile
index 41d330c..dfd822c 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 EXAMPLE_FILES := HelloWorld EchoServer BroadcastingEchoServer
 THREADED_EXAMPLE_FILES := HelloWorldThreaded EchoServerThreaded
-override CXXFLAGS += -lpthread -std=c++17 -Isrc -IuSockets/src
+override CXXFLAGS += -lpthread -Wconversion -std=c++17 -Isrc -IuSockets/src
 override LDFLAGS += uSockets/*.o -lz
 
 # WITH_OPENSSL=1 enables OpenSSL 1.1+ support
diff --git a/src/AsyncSocket.h b/src/AsyncSocket.h
index 61ee312..3957fed 100644
--- a/src/AsyncSocket.h
+++ b/src/AsyncSocket.h
@@ -82,7 +82,7 @@ protected:
         LoopData *loopData = getLoopData();
         if (loopData->corkedSocket == this && loopData->corkOffset + size < LoopData::CORK_BUFFER_SIZE) {
             char *sendBuffer = loopData->corkBuffer + loopData->corkOffset;
-            loopData->corkOffset += size;
+            loopData->corkOffset += (int) size;
             return {sendBuffer, false};
         } else {
             /* Slow path for now, we want to always be corked if possible */
@@ -92,7 +92,7 @@ protected:
 
     /* Returns the user space backpressure. */
     int getBufferedAmount() {
-        return getAsyncSocketData()->buffer.size();
+        return (int) getAsyncSocketData()->buffer.size();
     }
 
     /* Returns the remote IP address or empty string on failure */
@@ -118,7 +118,7 @@ protected:
         /* We are limited if we have a per-socket buffer */
         if (asyncSocketData->buffer.length()) {
             /* Write off as much as we can */
-            int written = us_socket_write(SSL, (us_socket_t *) this, asyncSocketData->buffer.data(), asyncSocketData->buffer.length(), /*nextLength != 0 | */length);
+            int written = us_socket_write(SSL, (us_socket_t *) this, asyncSocketData->buffer.data(), (int) asyncSocketData->buffer.length(), /*nextLength != 0 | */length);
 
             /* On failure return, otherwise continue down the function */
             if ((unsigned int) written < asyncSocketData->buffer.length()) {
diff --git a/src/HttpParser.h b/src/HttpParser.h
index 62333a9..a1c21e7 100644
--- a/src/HttpParser.h
+++ b/src/HttpParser.h
@@ -150,7 +150,7 @@ private:
             if (*postPaddedBuffer == '\r') {
                 if ((postPaddedBuffer != end) & (postPaddedBuffer[1] == '\n') & (i > 0)) {
                     headers->key = std::string_view(nullptr, 0);
-                    return (postPaddedBuffer + 2) - start;
+                    return (unsigned int) ((postPaddedBuffer + 2) - start);
                 } else {
                     return 0;
                 }
@@ -182,11 +182,11 @@ private:
             length -= consumed;
             consumedTotal += consumed;
 
-            req->headers->value = std::string_view(req->headers->value.data(), std::max<int>(0, req->headers->value.length() - 9));
+            req->headers->value = std::string_view(req->headers->value.data(), std::max<int>(0, (int) req->headers->value.length() - 9));
 
             /* Parse query */
             const char *querySeparatorPtr = (const char *) memchr(req->headers->value.data(), '?', req->headers->value.length());
-            req->querySeparator = (querySeparatorPtr ? querySeparatorPtr : req->headers->value.data() + req->headers->value.length()) - req->headers->value.data();
+            req->querySeparator = (int) ((querySeparatorPtr ? querySeparatorPtr : req->headers->value.data() + req->headers->value.length()) - req->headers->value.data());
 
             /* If returned socket is not what we put in we need
              * to break here as we either have upgraded to
@@ -257,16 +257,16 @@ public:
             }
 
         } else if (fallback.length()) {
-            int had = fallback.length();
+            int had = (int) fallback.length();
 
-            int maxCopyDistance = std::min(MAX_FALLBACK_SIZE - fallback.length(), (size_t) length);
+            int maxCopyDistance = (int) std::min(MAX_FALLBACK_SIZE - fallback.length(), (size_t) length);
 
             /* We don't want fallback to be short string optimized, since we want to move it */
             fallback.reserve(fallback.length() + maxCopyDistance + std::max<int>(MINIMUM_HTTP_POST_PADDING, sizeof(std::string)));
             fallback.append(data, maxCopyDistance);
 
             // break here on break
-            std::pair<int, void *> consumed = fenceAndConsumePostPadded<true>(fallback.data(), fallback.length(), user, &req, requestHandler, dataHandler);
+            std::pair<int, void *> consumed = fenceAndConsumePostPadded<true>(fallback.data(), (int) fallback.length(), user, &req, requestHandler, dataHandler);
             if (consumed.second != user) {
                 return consumed.second;
             }
diff --git a/src/HttpResponse.h b/src/HttpResponse.h
index 4053a86..76a027a 100644
--- a/src/HttpResponse.h
+++ b/src/HttpResponse.h
@@ -88,7 +88,7 @@ private:
 
         /* If no total size given then assume this chunk is everything */
         if (!totalSize) {
-            totalSize = data.length();
+            totalSize = (int) data.length();
         }
 
         HttpResponseData<SSL> *httpResponseData = getHttpResponseData();
@@ -99,11 +99,11 @@ private:
             /* Do not allow sending 0 chunk here */
             if (data.length()) {
                 Super::write("\r\n", 2);
-                writeUnsignedHex(data.length());
+                writeUnsignedHex((unsigned int) data.length());
                 Super::write("\r\n", 2);
 
                 /* Ignoring optional for now */
-                Super::write(data.data(), data.length());
+                Super::write(data.data(), (int) data.length());
             }
 
             /* Terminating 0 chunk */
@@ -138,7 +138,7 @@ private:
              * if it failed to drain any prior failed header writes */
 
             /* Write as much as possible without causing backpressure */
-            auto [written, failed] = Super::write(data.data(), data.length(), optional);
+            auto [written, failed] = Super::write(data.data(), (int) data.length(), optional);
             httpResponseData->offset += written;
 
             /* Success is when we wrote the entire thing without any failures */
@@ -185,7 +185,7 @@ public:
         httpResponseData->state |= HttpResponseData<SSL>::HTTP_STATUS_CALLED;
 
         Super::write("HTTP/1.1 ", 9);
-        Super::write(status.data(), status.length());
+        Super::write(status.data(), (int) status.length());
         Super::write("\r\n", 2);
         return this;
     }
@@ -194,16 +194,16 @@ public:
     HttpResponse *writeHeader(std::string_view key, std::string_view value) {
         writeStatus(HTTP_200_OK);
 
-        Super::write(key.data(), key.length());
+        Super::write(key.data(), (int) key.length());
         Super::write(": ", 2);
-        Super::write(value.data(), value.length());
+        Super::write(value.data(), (int) value.length());
         Super::write("\r\n", 2);
         return this;
     }
 
     /* Write an HTTP header with unsigned int value */
     HttpResponse *writeHeader(std::string_view key, unsigned int value) {
-        Super::write(key.data(), key.length());
+        Super::write(key.data(), (int) key.length());
         Super::write(": ", 2);
         writeUnsigned(value);
         Super::write("\r\n", 2);
@@ -212,7 +212,7 @@ public:
 
     /* End the response with an optional data chunk. Always starts a timeout. */
     void end(std::string_view data = {}) {
-        internalEnd(data, data.length(), false);
+        internalEnd(data, (int) data.length(), false);
     }
 
     /* Try and end the response. Returns [true, true] on success.
@@ -242,10 +242,10 @@ public:
         }
 
         Super::write("\r\n", 2);
-        writeUnsignedHex(data.length());
+        writeUnsignedHex((unsigned int) data.length());
         Super::write("\r\n", 2);
 
-        auto [written, failed] = Super::write(data.data(), data.length());
+        auto [written, failed] = Super::write(data.data(), (int) data.length());
         if (failed) {
             Super::timeout(HTTP_TIMEOUT_S);
         }
diff --git a/src/HttpRouter.h b/src/HttpRouter.h
index 3bd2aad..9ab8032 100644
--- a/src/HttpRouter.h
+++ b/src/HttpRouter.h
@@ -107,7 +107,7 @@ private:
     /* Set URL for router. Will reset any URL cache */
     inline void setUrl(std::string_view url) {
         /* Remove / from input URL */
-        currentUrl = url.substr(std::min<unsigned int>(url.length(), 1));
+        currentUrl = url.substr(std::min<unsigned int>((unsigned int) url.length(), 1));
         urlSegmentTop = -1;
     }
 
@@ -230,7 +230,7 @@ public:
                 node = getNode(node, std::string(getUrlSegment(i)));
             }
             /* Insert handler in order sorted by priority (most significant 1 byte) */
-            node->handlers.insert(std::upper_bound(node->handlers.begin(), node->handlers.end(), priority | handlers.size()), priority | handlers.size());
+            node->handlers.insert(std::upper_bound(node->handlers.begin(), node->handlers.end(), (uint32_t) (priority | handlers.size())), (uint32_t) (priority | handlers.size()));
         }
 
         /* Alloate this handler */
diff --git a/src/Utilities.h b/src/Utilities.h
index 123bbfc..c84029e 100644
--- a/src/Utilities.h
+++ b/src/Utilities.h
@@ -34,7 +34,7 @@ inline int u32toaHex(uint32_t value, char *dst) {
         value /= 16;
     } while (value > 0);
 
-    int ret = p - temp;
+    int ret = (int) (p - temp);
 
     do {
         *dst++ = *--p;
@@ -47,11 +47,11 @@ inline int u32toa(uint32_t value, char *dst) {
     char temp[10];
     char *p = temp;
     do {
-        *p++ = (char) (value % 10) + '0';
+        *p++ = (char) ((value % 10) + '0');
         value /= 10;
     } while (value > 0);
 
-    int ret = p - temp;
+    int ret = (int) (p - temp);
 
     do {
         *dst++ = *--p;
diff --git a/src/WebSocket.h b/src/WebSocket.h
index eb24526..9c36e32 100644
--- a/src/WebSocket.h
+++ b/src/WebSocket.h
@@ -84,7 +84,7 @@ public:
         auto[sendBuffer, requiresWrite] = Super::getSendBuffer(messageFrameSize);
         protocol::formatMessage<isServer>(sendBuffer, message.data(), message.length(), opCode, message.length(), compress);
         if (requiresWrite) {
-            auto[written, failed] = Super::write(sendBuffer, messageFrameSize);
+            auto[written, failed] = Super::write(sendBuffer, (int) messageFrameSize);
 
             /* For now, we are slow here (fix!) */
             free(sendBuffer);
@@ -110,9 +110,9 @@ public:
 
         /* Format and send the close frame */
         static const int MAX_CLOSE_PAYLOAD = 123;
-        int length = std::min<size_t>(MAX_CLOSE_PAYLOAD, message.length());
+        int length = (int) std::min<size_t>(MAX_CLOSE_PAYLOAD, message.length());
         char closePayload[MAX_CLOSE_PAYLOAD + 2];
-        int closePayloadLength = protocol::formatClosePayload(closePayload, code, message.data(), length);
+        int closePayloadLength = (int) protocol::formatClosePayload(closePayload, (uint16_t) code, message.data(), length);
         bool ok = send(std::string_view(closePayload, closePayloadLength), OpCode::CLOSE);
 
         /* FIN if we are ok and not corked */
diff --git a/src/WebSocketContext.h b/src/WebSocketContext.h
index 0e17ec9..fb96fa9 100644
--- a/src/WebSocketContext.h
+++ b/src/WebSocketContext.h
@@ -179,7 +179,7 @@ private:
             } else {
                 /* Here we never mind any size optimizations as we are in the worst possible path */
                 webSocketData->fragmentBuffer.append(data, length);
-                webSocketData->controlTipLength += length;
+                webSocketData->controlTipLength += (int) length;
 
                 if (!remainingBytes && fin) {
                     char *controlBuffer = (char *) webSocketData->fragmentBuffer.data() + webSocketData->fragmentBuffer.length() - webSocketData->controlTipLength;
diff --git a/src/WebSocketContextData.h b/src/WebSocketContextData.h
index d7e0af8..51b4f7f 100644
--- a/src/WebSocketContextData.h
+++ b/src/WebSocketContextData.h
@@ -57,7 +57,7 @@ struct WebSocketContextData {
         /* We rely on writing to regular asyncSockets */
         auto *asyncSocket = (AsyncSocket<SSL> *) s->user;
 
-        auto [written, failed] = asyncSocket->write(data.data(), data.length());
+        auto [written, failed] = asyncSocket->write(data.data(), (int) data.length());
         if (!failed) {
             asyncSocket->timeout(this->idleTimeout);
         } else {
diff --git a/src/WebSocketHandshake.h b/src/WebSocketHandshake.h
index 453473c..a539c75 100644
--- a/src/WebSocketHandshake.h
+++ b/src/WebSocketHandshake.h
@@ -120,10 +120,10 @@ public:
         for (int i = 0; i < 5; i++) {
             uint32_t tmp = b_output[i];
             char *bytes = (char *) &b_output[i];
-            bytes[3] = tmp & 0xff;
-            bytes[2] = (tmp >> 8) & 0xff;
-            bytes[1] = (tmp >> 16) & 0xff;
-            bytes[0] = (tmp >> 24) & 0xff;
+            bytes[3] = (char) (tmp & 0xff);
+            bytes[2] = (char) ((tmp >> 8) & 0xff);
+            bytes[1] = (char) ((tmp >> 16) & 0xff);
+            bytes[0] = (char) ((tmp >> 24) & 0xff);
         }
         base64((unsigned char *) b_output, output);
     }
diff --git a/src/WebSocketProtocol.h b/src/WebSocketProtocol.h
index d3c4159..ea69d1c 100644
--- a/src/WebSocketProtocol.h
+++ b/src/WebSocketProtocol.h
@@ -189,23 +189,23 @@ static inline size_t formatMessage(char *dst, const char *src, size_t length, Op
     size_t headerLength;
     if (reportedLength < 126) {
         headerLength = 2;
-        dst[1] = reportedLength;
+        dst[1] = (char) reportedLength;
     } else if (reportedLength <= UINT16_MAX) {
         headerLength = 4;
         dst[1] = 126;
-        uint16_t tmp = cond_byte_swap<uint16_t>(reportedLength);
+        uint16_t tmp = cond_byte_swap<uint16_t>((uint16_t) reportedLength);
         memcpy(&dst[2], &tmp, sizeof(uint16_t));
     } else {
         headerLength = 10;
         dst[1] = 127;
-        uint64_t tmp = cond_byte_swap<uint64_t>(reportedLength);
+        uint64_t tmp = cond_byte_swap<uint64_t>((uint64_t) reportedLength);
         memcpy(&dst[2], &tmp, sizeof(uint64_t));
     }
 
     int flags = 0;
-    dst[0] = (flags & SND_NO_FIN ? 0 : 128) | (compressed ? SND_COMPRESSED : 0);
+    dst[0] = (char) ((flags & SND_NO_FIN ? 0 : 128) | (compressed ? SND_COMPRESSED : 0));
     if (!(flags & SND_CONTINUATION)) {
-        dst[0] |= opCode;
+        dst[0] |= (char) opCode;
     }
 
     char mask[4];
@@ -320,7 +320,7 @@ protected:
             }
 
             src += payLength + MESSAGE_HEADER;
-            length -= payLength + MESSAGE_HEADER;
+            length -= (unsigned int) (payLength + MESSAGE_HEADER);
             wState->state.spillLength = 0;
             return false;
         } else {
@@ -419,7 +419,7 @@ public:
             }
             if (length) {
                 memcpy(wState->state.spill, src, length);
-                wState->state.spillLength = length;
+                wState->state.spillLength = length & 0xf;
             }
         } else if (consumeContinuation(src, length, wState, user)) {
             goto parseNext;