diff --git a/fastboot/socket.cpp b/fastboot/socket.cpp
index 14ecd93..e56ffcf 100644
--- a/fastboot/socket.cpp
+++ b/fastboot/socket.cpp
@@ -167,7 +167,7 @@
 // Implements the Socket interface for TCP.
 class TcpSocket : public Socket {
   public:
-    TcpSocket(cutils_socket_t sock) : Socket(sock) {}
+    explicit TcpSocket(cutils_socket_t sock) : Socket(sock) {}
 
     bool Send(const void* data, size_t length) override;
     bool Send(std::vector<cutils_socket_buffer_t> buffers) override;
diff --git a/fastboot/tcp.cpp b/fastboot/tcp.cpp
index e42c4e1..dd6fbf8 100644
--- a/fastboot/tcp.cpp
+++ b/fastboot/tcp.cpp
@@ -66,7 +66,7 @@
     int Close() override;
 
   private:
-    TcpTransport(std::unique_ptr<Socket> sock) : socket_(std::move(sock)) {}
+    explicit TcpTransport(std::unique_ptr<Socket> sock) : socket_(std::move(sock)) {}
 
     // Connects to the device and performs the initial handshake. Returns false and fills |error|
     // on failure.
diff --git a/fastboot/udp.cpp b/fastboot/udp.cpp
index b36bd60..53fb347 100644
--- a/fastboot/udp.cpp
+++ b/fastboot/udp.cpp
@@ -111,7 +111,7 @@
     int Close() override;
 
   private:
-    UdpTransport(std::unique_ptr<Socket> socket) : socket_(std::move(socket)) {}
+    explicit UdpTransport(std::unique_ptr<Socket> socket) : socket_(std::move(socket)) {}
 
     // Performs the UDP initialization procedure. Returns true on success.
     bool InitializeProtocol(std::string* error);
diff --git a/fastboot/usb_linux.cpp b/fastboot/usb_linux.cpp
index d4824fb..6db1e27 100644
--- a/fastboot/usb_linux.cpp
+++ b/fastboot/usb_linux.cpp
@@ -89,7 +89,7 @@
 
 class LinuxUsbTransport : public Transport {
   public:
-    LinuxUsbTransport(std::unique_ptr<usb_handle> handle) : handle_(std::move(handle)) {}
+    explicit LinuxUsbTransport(std::unique_ptr<usb_handle> handle) : handle_(std::move(handle)) {}
     ~LinuxUsbTransport() override = default;
 
     ssize_t Read(void* data, size_t len) override;