diff --git a/lrzip_private.h b/lrzip_private.h
index 1aa41ce..ed5efb1 100644
--- a/lrzip_private.h
+++ b/lrzip_private.h
@@ -178,7 +178,6 @@ struct rzip_control {
 	long page_size;
 	int fd_out;
 	md5_ctx ctx;
-	void *data; // random data pointer associated for use in callbacks
 	i64 md5_read; // How far into the file the md5 has done so far
 };
 
diff --git a/stream.c b/stream.c
index aff4a8f..c0ed349 100644
--- a/stream.c
+++ b/stream.c
@@ -77,6 +77,16 @@ static struct uncomp_thread{
 	int stream;
 } *ucthread;
 
+typedef struct stream_thread_struct {
+	int i;
+	rzip_control *control;
+} stream_thread_struct;
+
+static long output_thread;
+static pthread_mutex_t output_lock = PTHREAD_MUTEX_INITIALIZER;
+static pthread_cond_t output_cond = PTHREAD_COND_INITIALIZER;
+static pthread_t *threads;
+
 static void init_mutex(pthread_mutex_t *mutex)
 {
 	if (unlikely(pthread_mutex_init(mutex, NULL)))
@@ -752,8 +762,6 @@ static int seekto(struct stream_info *sinfo, i64 pos)
 	return 0;
 }
 
-static pthread_t *threads;
-
 void prepare_streamout_threads(rzip_control *control)
 {
 	int i;
@@ -778,9 +786,6 @@ void prepare_streamout_threads(rzip_control *control)
 		init_mutex(&cthread[i].mutex);
 }
 
-static long output_thread;
-static pthread_mutex_t output_lock = PTHREAD_MUTEX_INITIALIZER;
-static pthread_cond_t output_cond = PTHREAD_COND_INITIALIZER;
 
 void close_streamout_threads(rzip_control *control)
 {
@@ -991,13 +996,17 @@ failed:
  * backend compression and is then freed here */
 static void *compthread(void *data)
 {
-	rzip_control *control = data;
-	long i = (long)control->data;
-	control->data = NULL;
-	struct compress_thread *cti = &cthread[i];
-	struct stream_info *ctis = cti->sinfo;
+	stream_thread_struct *s = data;
+	rzip_control *control = s->control;
+	long i = s->i;
+	struct compress_thread *cti;
+	struct stream_info *ctis;
 	int waited = 0, ret = 0;
 
+	free(data);
+	cti = &cthread[i];
+	ctis = cti->sinfo;
+
 	if (unlikely(setpriority(PRIO_PROCESS, 0, control->nice_val) == -1))
 		print_err("Warning, unable to set nice value on thread\n");
 
@@ -1098,6 +1107,7 @@ retry:
 static void clear_buffer(rzip_control *control, struct stream_info *sinfo, int stream, int newbuf)
 {
 	static long i = 0;
+	stream_thread_struct *s;
 
 	/* Make sure this thread doesn't already exist */
 	lock_mutex(&cthread[i].mutex);
@@ -1109,8 +1119,13 @@ static void clear_buffer(rzip_control *control, struct stream_info *sinfo, int s
 
 	print_maxverbose("Starting thread %ld to compress %lld bytes from stream %d\n",
 			 i, cthread[i].s_len, stream);
-	control->data = (void*)i;
-	create_pthread(&threads[i], NULL, compthread, control);
+
+	s = malloc(sizeof(stream_thread_struct));
+	if (unlikely(!s))
+		fatal("Unable to malloc in clear_buffer");
+	s->i = i;
+	s->control = control;
+	create_pthread(&threads[i], NULL, compthread, s);
 
 	if (newbuf) {
 		/* The stream buffer has been given to the thread, allocate a new one */
@@ -1132,12 +1147,15 @@ void flush_buffer(rzip_control *control, struct stream_info *sinfo, int stream)
 
 static void *ucompthread(void *data)
 {
-	rzip_control *control = data;
-	long i = (long)control->data;
-	control->data = NULL;
-	struct uncomp_thread *uci = &ucthread[i];
+	stream_thread_struct *s = data;
+	rzip_control *control = s->control;
+	long i = s->i;
+	struct uncomp_thread *uci;
 	int waited = 0, ret = 0;
 
+	free(data);
+	uci = &ucthread[i];
+
 	if (unlikely(setpriority(PRIO_PROCESS, 0, control->nice_val) == -1))
 		print_err("Warning, unable to set nice value on thread\n");
 
@@ -1193,6 +1211,7 @@ static int fill_buffer(rzip_control *control, struct stream_info *sinfo, int str
 	i64 header_length, u_len, c_len, last_head;
 	struct stream *s = &sinfo->s[stream];
 	uchar c_type, *s_buf;
+	stream_thread_struct *st;
 
 	if (s->buf)
 		free(s->buf);
@@ -1257,8 +1276,13 @@ fill_another:
 	ucthread[s->uthread_no].busy = 1;
 	print_maxverbose("Starting thread %ld to decompress %lld bytes from stream %d\n",
 			 s->uthread_no, c_len, stream);
-	control->data = (void*)s->uthread_no;
-	create_pthread(&threads[s->uthread_no], NULL, ucompthread, control);
+
+	st = malloc(sizeof(stream_thread_struct));
+	if (unlikely(!st))
+		fatal("Unable to malloc in fill_buffer");
+	st->i = s->uthread_no;
+	st->control = control;
+	create_pthread(&threads[s->uthread_no], NULL, ucompthread, st);
 
 	if (++s->uthread_no == s->base_thread + s->total_threads)
 		s->uthread_no = s->base_thread;