diff --git a/meshcore/zlib/zlib.h b/meshcore/zlib/zlib.h
index f09cdaf..7496b2d 100644
--- a/meshcore/zlib/zlib.h
+++ b/meshcore/zlib/zlib.h
@@ -1722,7 +1722,7 @@ ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
    negative, the result has no meaning or utility.
 */
 
-ZEXTERN uLong ZEXPORT crc32   OF((uLong crc, const Bytef *buf, uInt len));
+//ZEXTERN uLong ZEXPORT crc32   OF((uLong crc, const Bytef *buf, uInt len));
 /*
      Update a running CRC-32 with the bytes buf[0..len-1] and return the
    updated CRC-32.  If buf is Z_NULL, this function returns the required
diff --git a/microscript/ILibDuktape_CompressedStream.c b/microscript/ILibDuktape_CompressedStream.c
index 779c051..3189442 100644
--- a/microscript/ILibDuktape_CompressedStream.c
+++ b/microscript/ILibDuktape_CompressedStream.c
@@ -29,6 +29,8 @@ limitations under the License.
 
 #define ILibDuktape_CompressorStream_ptr			"\xFF_Duktape_CompressorStream_ptr"
 #define ILibDuktape_CompressorStream_ResumeBuffer	"\xFF_Duktape_CompressorStream_ResumeBuffer"
+extern uint32_t crc32(uint32_t crc, const unsigned char* buf, uint32_t len);
+
 typedef struct ILibDuktape_CompressorStream
 {
 	duk_context *ctx;