diff --git a/lib/zstd/decompress.c b/lib/zstd/decompress.c
index 8203b81..19bf712 100644
--- a/lib/zstd/decompress.c
+++ b/lib/zstd/decompress.c
@@ -123,7 +123,7 @@
 	return 0;
 }
 
-ZSTD_DCtx *ZSTD_createDCtx_advanced(ZSTD_customMem customMem)
+static ZSTD_DCtx *ZSTD_createDCtx_advanced(ZSTD_customMem customMem)
 {
 	ZSTD_DCtx *dctx;
 
@@ -391,7 +391,7 @@
 
 /*! ZSTD_getcBlockSize() :
 *   Provides the size of compressed block from block header `src` */
-size_t ZSTD_getcBlockSize(const void *src, size_t srcSize, blockProperties_t *bpPtr)
+static size_t ZSTD_getcBlockSize(const void *src, size_t srcSize, blockProperties_t *bpPtr)
 {
 	if (srcSize < ZSTD_blockHeaderSize)
 		return ERROR(srcSize_wrong);
@@ -429,7 +429,7 @@
 
 /*! ZSTD_decodeLiteralsBlock() :
 	@return : nb of bytes read from src (< srcSize ) */
-size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx *dctx, const void *src, size_t srcSize) /* note : srcSize < BLOCKSIZE */
+static size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx *dctx, const void *src, size_t srcSize) /* note : srcSize < BLOCKSIZE */
 {
 	if (srcSize < MIN_CBLOCK_SIZE)
 		return ERROR(corruption_detected);
@@ -791,7 +791,7 @@
 	}
 }
 
-size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx *dctx, int *nbSeqPtr, const void *src, size_t srcSize)
+static size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx *dctx, int *nbSeqPtr, const void *src, size_t srcSize)
 {
 	const BYTE *const istart = (const BYTE *const)src;
 	const BYTE *const iend = istart + srcSize;
@@ -1494,7 +1494,7 @@
 	return blockSize;
 }
 
-size_t ZSTD_generateNxBytes(void *dst, size_t dstCapacity, BYTE byte, size_t length)
+static size_t ZSTD_generateNxBytes(void *dst, size_t dstCapacity, BYTE byte, size_t length)
 {
 	if (length > dstCapacity)
 		return ERROR(dstSize_tooSmall);