diff --git a/src/lbx_zlib/lbx_zlib.h b/src/lbx_zlib/lbx_zlib.h

index 4e533f3..b990e2f 100644

--- a/src/lbx_zlib/lbx_zlib.h

+++ b/src/lbx_zlib/lbx_zlib.h

@@ -135,9 +135,9 @@ extern int FlushIovBuf ( int fd, struct iovec *iovbuf );

 #endif

 /* lbx_zlib.c */

-unsigned long stream_out_compressed;

-unsigned long stream_out_uncompressed;

-unsigned long stream_out_plain;

-unsigned long stream_in_compressed;

-unsigned long stream_in_uncompressed;

-unsigned long stream_in_plain;

+extern unsigned long stream_out_compressed;

+extern unsigned long stream_out_uncompressed;

+extern unsigned long stream_out_plain;

+extern unsigned long stream_in_compressed;

+extern unsigned long stream_in_uncompressed;

+extern unsigned long stream_in_plain;