diff --git a/src/Makefile b/src/Makefile
index 65a2c9c..c6132e0 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -1,21 +1,16 @@
-
-all:  librpitx 
-
-CFLAGS	= -Wall -O3 -Wno-unused-variable 
-LDFLAGS	= -lm -lrt -lpthread 
-CCP = g++ 
-CC = gcc 
+CFLAGS = -Wall -O3 -Wno-unused-variable
+CXXFLAGS = -std=c++11 -Wall -O3 -Wno-unused-variable
+LDFLAGS = -lm -lrt -lpthread
+CCP = c++
+CC = cc
 
 librpitx: librpitx.h gpio.h gpio.cpp dma.h dma.cpp mailbox.c raspberry_pi_revision.c fmdmasync.h fmdmasync.cpp ngfmdmasync.h ngfmdmasync.cpp dsp.h dsp.cpp iqdmasync.h iqdmasync.cpp serialdmasync.h serialdmasync.cpp phasedmasync.h phasedmasync.cpp fskburst.h fskburst.cpp
 	$(CC) $(CFLAGS) -c -o mailbox.o mailbox.c
 	$(CC) $(CFLAGS) -c -o raspberry_pi_revision.o raspberry_pi_revision.c
-	$(CCP) $(CFLAGS) -c dsp.cpp iqdmasync.cpp ngfmdmasync.cpp fmdmasync.cpp  dma.cpp gpio.cpp serialdmasync.cpp phasedmasync.cpp amdmasync.h amdmasync.cpp fskburst.cpp
+	$(CCP) $(CXXFLAGS) -c dsp.cpp iqdmasync.cpp ngfmdmasync.cpp fmdmasync.cpp  dma.cpp gpio.cpp serialdmasync.cpp phasedmasync.cpp amdmasync.h amdmasync.cpp fskburst.cpp
 	$(AR) rc librpitx.a dsp.o iqdmasync.o ngfmdmasync.o fmdmasync.o  dma.o gpio.o mailbox.o raspberry_pi_revision.o  serialdmasync.o phasedmasync.o amdmasync.o fskburst.o
 
+install: librpitx
 
 clean:
-	
-	rm -f  *.o *.a
-
-#install: all
-	
+	rm -f *.o *.a
diff --git a/src/amdmasync.cpp b/src/amdmasync.cpp
index ff4d76a..fc51c53 100644
--- a/src/amdmasync.cpp
+++ b/src/amdmasync.cpp
@@ -22,6 +22,7 @@ This program is free software: you can redistribute it and/or modify
 #include <math.h>
 #include <time.h>
 #include <sched.h>
+#include <stdlib.h>
 
 
 amdmasync::amdmasync(uint64_t TuneFrequency,uint32_t SR,int Channel,uint32_t FifoSize):bufferdma(Channel,FifoSize,3,2)
diff --git a/src/dsp.cpp b/src/dsp.cpp
index 33f26f6..e6ff654 100644
--- a/src/dsp.cpp
+++ b/src/dsp.cpp
@@ -17,6 +17,7 @@ This program is free software: you can redistribute it and/or modify
 
 
 #include "dsp.h"
+#include <stdlib.h>
 
 dsp::dsp()
 {
diff --git a/src/gpio.cpp b/src/gpio.cpp
index 7689acf..00160d6 100644
--- a/src/gpio.cpp
+++ b/src/gpio.cpp
@@ -116,7 +116,7 @@ uint64_t clkgpio::GetPllFrequency(int PllNo)
 		Freq = XOSC_FREQUENCY * ((uint64_t)gpioreg[PLLH_CTRL] & 0x3ff) + XOSC_FREQUENCY * (uint64_t)gpioreg[PLLH_FRAC] / (1 << 20);
 		break;
 	}
-	fprintf(stderr, "Freq = %lld\n", Freq);
+	fprintf(stderr, "Freq = %lu\n", Freq);
 
 	return Freq;
 }
diff --git a/src/mailbox.c b/src/mailbox.c
index 4ef05ca..e172615 100644
--- a/src/mailbox.c
+++ b/src/mailbox.c
@@ -63,7 +63,7 @@ void *mapmem(unsigned base, unsigned size)
    printf("base=0x%x, mem=%p\n", base, mem);
 #endif
    if (mem == MAP_FAILED) {
-      printf("mmap error %d\n", (int)mem);
+      printf("mmap error %p\n", mem);
       exit (-1);
    }
    close(mem_fd);