diff --git a/src/cpulimit.c b/src/cpulimit.c
index 50eabeac..1735b04a 100644
--- a/src/cpulimit.c
+++ b/src/cpulimit.c
@@ -38,12 +38,11 @@
 #include <string.h>
 #include <sys/stat.h>
 #include <sys/time.h>
-#include <sys/sysctl.h>
 #include <sys/resource.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 
-#ifdef __APPLE__ || __FREEBSD__
+#if defined(__APPLE__) || defined(__FREEBSD__)
 #include <libgen.h>
 #endif
 
diff --git a/src/process_group.c b/src/process_group.c
index 06d73a6f..18ecac1e 100644
--- a/src/process_group.c
+++ b/src/process_group.c
@@ -24,6 +24,11 @@
 #include <limits.h>
 #include <sys/time.h>
 #include <signal.h>
+#include <libgen.h>
+
+#if defined(__APPLE__) || defined(__FREEBSD__)
+#include <libgen.h>
+#endif
 
 #include <assert.h>
 
diff --git a/src/process_iterator.c b/src/process_iterator.c
index 8b4019d2..5b6c651b 100644
--- a/src/process_iterator.c
+++ b/src/process_iterator.c
@@ -22,9 +22,6 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#ifndef __APPLE__
-#include <sys/procfs.h>
-#endif
 #include <time.h>
 #include "process_iterator.h"
 
diff --git a/src/process_iterator_linux.c b/src/process_iterator_linux.c
index c8cdd07a..93b44bab 100644
--- a/src/process_iterator_linux.c
+++ b/src/process_iterator_linux.c
@@ -98,6 +98,7 @@ static int read_process_info(pid_t pid, struct process *p)
 	//read command line
 	sprintf(exefile,"/proc/%d/cmdline", p->pid);
 	fd = fopen(exefile, "r");
+	if (fd==NULL) return -1;
 	if (fgets(buffer, sizeof(buffer), fd)==NULL) {
 		fclose(fd);
 		return -1;
diff --git a/tests/busy.c b/tests/busy.c
index b3afb7cd..93f0bcce 100644
--- a/tests/busy.c
+++ b/tests/busy.c
@@ -3,7 +3,7 @@
 #include <pthread.h>
 #include <unistd.h>
 
-void *loop()
+void *loop(void *)
 {
 	while(1);
 }
@@ -23,7 +23,7 @@ int main(int argc, char **argv) {
 			exit(1);
 		}
 	}
-	loop();
+	loop(NULL);
 	return 0;
 }
 
diff --git a/tests/process_iterator_test.c b/tests/process_iterator_test.c
index 16151967..1bfc167b 100644
--- a/tests/process_iterator_test.c
+++ b/tests/process_iterator_test.c
@@ -28,7 +28,7 @@
 #include <signal.h>
 #include <string.h>
 
-#ifdef __APPLE__ || __FREEBSD__
+#if defined(__APPLE__) || defined(__FREEBSD__)
 #include <libgen.h>
 #endif