diff --git a/turbojpeg.c b/turbojpeg.c
index 3a4460b..ff2b266 100644
--- a/turbojpeg.c
+++ b/turbojpeg.c
@@ -40,6 +40,10 @@
 #include "./tjutil.h"
 #include "transupp.h"
 
+#if !_WIN32
+#define _putenv putenv
+#endif
+
 extern void jpeg_mem_dest_tj(j_compress_ptr, unsigned char **,
 	unsigned long *, boolean);
 extern void jpeg_mem_src_tj(j_decompress_ptr, unsigned char *, unsigned long);