diff --git a/boards/msba2-common/tools/src/download.c b/boards/msba2-common/tools/src/download.c
index 6a6229cdb7..3fa338d4e9 100644
--- a/boards/msba2-common/tools/src/download.c
+++ b/boards/msba2-common/tools/src/download.c
@@ -854,7 +854,7 @@ static void download_main(int event)
                         // bootloader again.  Intead, we need to download a tiny ARM
                         // program that reconfigures the hardware and then jumps to zero.
                         //snprintf(buf, sizeof(buf), "G %d A\r\n", 0);
-                        snprintf(buf, sizeof(buf), "W %u %d\r\n", chip->ram_addr, chip->bootprog[0] * 4);
+                        snprintf(buf, sizeof(buf), "W %u %u\r\n", chip->ram_addr, chip->bootprog[0] * 4);
                         xmit_cmd(buf, 4);
                         return;
 
diff --git a/boards/msba2-common/tools/src/ihex.c b/boards/msba2-common/tools/src/ihex.c
index 5db4cb7511..8d4965b9d5 100644
--- a/boards/msba2-common/tools/src/ihex.c
+++ b/boards/msba2-common/tools/src/ihex.c
@@ -120,8 +120,8 @@ int read_intel_hex(const char *filename)
 int
 parse_hex_line(char *line)
 {
-    int addr, code, num;
-    int sum, len, cksum, i;
+    unsigned int addr, code, num;
+    unsigned int sum, len, cksum, i;
     char *ptr;
 
     num = 0;
diff --git a/core/assert.c b/core/assert.c
index 35c9d5359e..873634467d 100644
--- a/core/assert.c
+++ b/core/assert.c
@@ -20,7 +20,7 @@
 #ifdef DEBUG_ASSERT_VERBOSE
 NORETURN void _assert_failure(const char *file, unsigned line)
 {
-    printf("%s:%d => ", file, line); \
+    printf("%s:%u => ", file, line); \
     core_panic(PANIC_ASSERT_FAIL, assert_crash_message); \
 }
 #else
diff --git a/cpu/lm4f120/periph/gpio.c b/cpu/lm4f120/periph/gpio.c
index 76ded871e2..24660a95e6 100644
--- a/cpu/lm4f120/periph/gpio.c
+++ b/cpu/lm4f120/periph/gpio.c
@@ -98,7 +98,7 @@ int gpio_init(gpio_t pin, gpio_mode_t mode)
     const uint32_t port_addr = _port_base[port_num];
     const uint8_t pin_num = _pin_num(pin);
     const uint32_t sysctl_port_base = _sysctl_port_base[port_num];
-    const unsigned long pin_bit = 1 << pin_num;
+    const unsigned long pin_bit = 1ul << pin_num;
 
     DEBUG("Init GPIO: port %c, %d\n", 'A' + port_num, pin_num);
     DEBUG("Sysctl %" PRIx32 "\n", sysctl_port_base);
diff --git a/cpu/lpc2387/mci/lpc2387-mci.c b/cpu/lpc2387/mci/lpc2387-mci.c
index 77207ed117..a1045f510a 100644
--- a/cpu/lpc2387/mci/lpc2387-mci.c
+++ b/cpu/lpc2387/mci/lpc2387-mci.c
@@ -380,6 +380,8 @@ static int send_cmd(unsigned int idx, unsigned long arg, unsigned int rt, unsign
 {
     unsigned int s, mc;
 
+    assert(buff != NULL);
+
     if (idx & 0x80) {               /* Send a CMD55 prior to the specified command if it is ACMD class */
         if (!send_cmd(CMD55, (unsigned long)CardRCA << 16, 1, buff) /* When CMD55 is faild, */
            || !(buff[0] & 0x00000020)) {
diff --git a/dist/tools/cppcheck/check.sh b/dist/tools/cppcheck/check.sh
index c2d153bf43..b79884fafb 100755
--- a/dist/tools/cppcheck/check.sh
+++ b/dist/tools/cppcheck/check.sh
@@ -17,7 +17,7 @@ else
 fi
 
 BRANCH=${1}
-FILEREGEX='\.([sScHh]|cpp)$'
+FILEREGEX='\.([CcHhSs]|[ch]pp)$'
 EXCLUDE='^(cpu/saml21/include/atmel/)|^(cpu/cortexm_common/include/)'
 
 # If no branch but an option is given, unset BRANCH.
diff --git a/sys/arduino/include/serialport.hpp b/sys/arduino/include/serialport.hpp
index c373afbbb3..f9a22ca0fd 100644
--- a/sys/arduino/include/serialport.hpp
+++ b/sys/arduino/include/serialport.hpp
@@ -55,7 +55,7 @@ public:
      *
      * @param[in] dev       RIOT UART device
      */
-    SerialPort(uart_t dev);
+    explicit SerialPort(uart_t dev);
 
     /**
      * @brief   Get the number of bytes (characters) available for reading from