diff --git a/rzip.c b/rzip.c
index 7a6a8e1..9b0e810 100644
--- a/rzip.c
+++ b/rzip.c
@@ -522,6 +522,13 @@ static void init_hash_indexes(struct rzip_state *st)
 
 extern const i64 one_g;
 
+static inline void *fake_mremap(void *old_address, size_t old_size, size_t new_size, int flags)
+{
+	flags = 0;
+	munmap(old_address, old_size);
+	return mmap(old_address, new_size, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+}
+
 /* stdin is not file backed so we have to emulate the mmap by mapping
  * anonymous ram and reading stdin into it. It means the maximum ram
  * we can use will be less but we will already have determined this in
diff --git a/rzip.h b/rzip.h
index 5452c39..9e60ef8 100644
--- a/rzip.h
+++ b/rzip.h
@@ -33,6 +33,8 @@
 #include <stdlib.h>
 #include <string.h>
 #include <signal.h>
+#include <bzlib.h>
+#include <zlib.h>
 #include <sys/resource.h>
 #include <netinet/in.h>
 
@@ -43,11 +45,23 @@
 
 #ifdef __APPLE__
 #include <sys/sysctl.h>
+#define fmemopen fake_fmemopen
+#define open_memstream fake_open_memstream
+#define memstream_update_buffer fake_open_memstream_update_buffer
+#define mremap fake_mremap
+#ifndef MAP_ANONYMOUS
+#define MAP_ANONYMOUS MAP_ANON
+#endif
+#else /* __APPLE__ */
+#define memstream_update_buffer(A, B, C) (0)
 #endif
 
 #include <lzo/lzoconf.h>
 #include <lzo/lzo1x.h>
 
+/* LZMA C Wrapper */
+#include "lzma/C/LzmaLib.h"
+
 #ifdef HAVE_STRING_H
 #include <string.h>
 #endif
diff --git a/stream.c b/stream.c
index 2875369..93e34d8 100644
--- a/stream.c
+++ b/stream.c
@@ -19,13 +19,7 @@
 /* multiplex N streams into a file - the streams are passed
    through different compressors */
 
-/* Need a definitition for FILE for old bzlib.h */
-#include <stdio.h>
-#include <bzlib.h>
-#include <zlib.h>
 #include "rzip.h"
-/* LZMA C Wrapper */
-#include "lzma/C/LzmaLib.h"
 
 #define STREAM_BUFSIZE (1024 * 1024 * 10)
 
@@ -52,12 +46,7 @@ struct stream_info {
 
 static int lzo_compresses(struct stream *s);
 
-#ifndef HAS_MEMSTREAM
-#define fmemopen fake_fmemopen
-#define open_memstream fake_open_memstream
-#define memstream_update_buffer fake_open_memstream_update_buffer
-
-static FILE *fake_fmemopen(void *buf, size_t buflen, char *mode)
+static inline FILE *fake_fmemopen(void *buf, size_t buflen, char *mode)
 {
 	FILE *in;
 
@@ -72,7 +61,7 @@ static FILE *fake_fmemopen(void *buf, size_t buflen, char *mode)
         return in;
 }
 
-static FILE *fake_open_memstream(char **buf, size_t *length)
+static inline FILE *fake_open_memstream(char **buf, size_t *length)
 {
 	FILE *out;
 
@@ -84,7 +73,7 @@ static FILE *fake_open_memstream(char **buf, size_t *length)
 	return out;
 }
 
-static int fake_open_memstream_update_buffer(FILE *fp, uchar **buf, size_t *length)
+static inline int fake_open_memstream_update_buffer(FILE *fp, uchar **buf, size_t *length)
 {
 	long original_pos = ftell(fp);
 
@@ -101,12 +90,6 @@ static int fake_open_memstream_update_buffer(FILE *fp, uchar **buf, size_t *leng
 	        return -1;
 	return 0;
 }
-#else
-static int memstream_update_buffer(FILE *fp, uchar **buf, size_t *length)
-{
-	return 0;
-}
-#endif
 
 /*
   ***** COMPRESSION FUNCTIONS *****
@@ -120,9 +103,9 @@ static int memstream_update_buffer(FILE *fp, uchar **buf, size_t *length)
 
 static void zpaq_compress_buf(struct stream *s, int *c_type, i64 *c_len)
 {
+	uchar *c_buf = NULL;
+	size_t dlen = 0;
 	FILE *in, *out;
-	uchar *c_buf;
-	size_t dlen;
 
 	if (!lzo_compresses(s))
 		return;
@@ -316,9 +299,9 @@ out_free:
 
 static int zpaq_decompress_buf(struct stream *s)
 {
+	uchar *c_buf = NULL;
+	size_t dlen = 0;
 	FILE *in, *out;
-	uchar *c_buf;
-	size_t dlen;
 
 	in = fmemopen(s->buf, s->buflen, "r");
 	if (!in) {