diff --git a/gpioclk.cpp b/gpioclk.cpp
index 7391d7b..915e062 100644
--- a/gpioclk.cpp
+++ b/gpioclk.cpp
@@ -52,7 +52,7 @@ using namespace std;
 // Choose proper base address depending on RPI1/RPI2 setting from makefile.
 #ifdef RPI2
 #define BCM2708_PERI_BASE 0x3f000000
-#pragma message "Raspberry Pi 2 detected."
+#pragma message "Raspberry Pi 2/3 detected."
 #else
 #define BCM2708_PERI_BASE 0x20000000
 #pragma message "Raspberry Pi 1 detected."
diff --git a/mailbox.c b/mailbox.c
index a04b38d..8336eba 100644
--- a/mailbox.c
+++ b/mailbox.c
@@ -247,7 +247,7 @@ int mbox_open() {
     // Open a char device file used for communicating with kernel mbox driver.
     file_desc = open(DEVICE_FILE_NAME, 0);
     if(file_desc >= 0) {
-        printf("Using mbox device " DEVICE_FILE_NAME ".\n");
+        //printf("Using mbox device " DEVICE_FILE_NAME ".\n");
         return file_desc;
     }
     
@@ -255,14 +255,14 @@ int mbox_open() {
     unlink(LOCAL_DEVICE_FILE_NAME);
     if(mknod(LOCAL_DEVICE_FILE_NAME, S_IFCHR|0600, makedev(MAJOR_NUM_A, 0)) >= 0 &&
         (file_desc = open(LOCAL_DEVICE_FILE_NAME, 0)) >= 0) {
-        printf("Using local mbox device file with major %d.\n", MAJOR_NUM_A);
+        //printf("Using local mbox device file with major %d.\n", MAJOR_NUM_A);
         return file_desc;
     }
 
     unlink(LOCAL_DEVICE_FILE_NAME);
     if(mknod(LOCAL_DEVICE_FILE_NAME, S_IFCHR|0600, makedev(MAJOR_NUM_B, 0)) >= 0 &&
         (file_desc = open(LOCAL_DEVICE_FILE_NAME, 0)) >= 0) {
-        printf("Using local mbox device file with major %d.\n", MAJOR_NUM_B);
+        //printf("Using local mbox device file with major %d.\n", MAJOR_NUM_B);
         return file_desc;
     }
 
diff --git a/mailbox.h b/mailbox.h
index 80bacb0..d1e49f2 100644
--- a/mailbox.h
+++ b/mailbox.h
@@ -30,7 +30,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #define MAJOR_NUM_B 100
 #define IOCTL_MBOX_PROPERTY _IOWR(MAJOR_NUM_B, 0, char *)
 #define DEVICE_FILE_NAME "/dev/vcio"
-#define LOCAL_DEVICE_FILE_NAME "mbox"
+#define LOCAL_DEVICE_FILE_NAME "/tmp/mbox"
 
 int mbox_open();
 void mbox_close(int file_desc);
diff --git a/makefile b/makefile
index dac7964..da3fafc 100644
--- a/makefile
+++ b/makefile
@@ -5,10 +5,10 @@ pi_version_flag = $(if $(call archis,armv7,dummy-text),-DRPI2,-DRPI1)
 
 all: wspr gpioclk
 
-mailbox.o:
+mailbox.o: mailbox.c mailbox.h
 	g++ -c -Wall -lm mailbox.c
 
-wspr: mailbox.o wspr.cpp
+wspr: mailbox.o wspr.cpp mailbox.h
 	g++ -Wall -lm $(pi_version_flag) mailbox.o wspr.cpp -owspr
 
 gpioclk: gpioclk.cpp
diff --git a/wspr.cpp b/wspr.cpp
index 3ffc169..e0f121e 100644
--- a/wspr.cpp
+++ b/wspr.cpp
@@ -74,7 +74,7 @@ using namespace std;
 #ifdef RPI2
 #define BCM2708_PERI_BASE 0x3f000000
 #define MEM_FLAG 0x04
-#pragma message "Raspberry Pi 2 detected."
+#pragma message "Raspberry Pi 2/3 detected."
 #else
 #define BCM2708_PERI_BASE 0x20000000
 #define MEM_FLAG 0x0c
@@ -670,7 +670,8 @@ void print_usage() {
   cout << "  -p --ppm ppm" << endl;
   cout << "    Known PPM correction to 19.2MHz RPi nominal crystal frequency." << endl;
   cout << "  -s --self-calibration" << endl;
-  cout << "    Call ntp_adjtime() before every transmission to obtain the PPM error of the crystal." << endl;
+  cout << "    Call ntp_adjtime() before every transmission to obtain the PPM error of the" << endl;
+  cout << "    crystal." << endl;
   cout << "  -r --repeat" << endl;
   cout << "    Repeatedly, and in order, transmit on all the specified command line freqs." << endl;
   cout << "  -x --terminate <n>" << endl;
@@ -680,7 +681,7 @@ void print_usage() {
   cout << "      +/- " << WSPR_RAND_OFFSET << " Hz for WSPR" << endl;
   cout << "      +/- " << WSPR15_RAND_OFFSET << " Hz for WSPR-15" << endl;
   cout << "  -t --test-tone freq" << endl;
-  cout << "    Simply output a test tone and the specified frequency. Only used" << endl;
+  cout << "    Simply output a test tone at the specified frequency. Only used" << endl;
   cout << "    for debugging and to verify calibration." << endl;
   cout << "  -n --no-delay" << endl;
   cout << "    Transmit immediately, do not wait for a WSPR TX window. Used" << endl;
@@ -911,7 +912,8 @@ void parse_commandline(
     cout << temp.str();
     temp.str("");
     if (self_cal) {
-      temp << "  ntp_adjtime() will be used to peridocially calibrate the transmission frequency" << endl;
+      temp << "  ntp_adjtime() will be used to peridocially calibrate the transmission" << endl;
+      temp << "    frequency" << endl;
     } else if (ppm) {
       temp << "  PPM value to be used for all transmissions: " << ppm << endl;
     }
@@ -1004,7 +1006,14 @@ void open_mbox()
     }
 }
 
+void unlinkmbox() {
+  unlink(DEVICE_FILE_NAME);
+  unlink(LOCAL_DEVICE_FILE_NAME);
+};
+
 int main(const int argc, char * const argv[]) {
+  atexit(unlinkmbox);
+
   // Initialize the RNG
   srand(time(NULL));