diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index c31f8db9..cc69f118 100644
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -32,7 +32,10 @@ typedef enum { ZSTDcs_created=0, ZSTDcs_init, ZSTDcs_ongoing, ZSTDcs_ending } ZS
 *  Helper functions
 ***************************************/
 #define ZSTD_STATIC_ASSERT(c) { enum { ZSTD_static_assert = 1/(int)(!!(c)) }; }
-size_t ZSTD_compressBound(size_t srcSize) { return FSE_compressBound(srcSize) + 12; }
+size_t ZSTD_compressBound(size_t srcSize) {
+    size_t const margin = (srcSize < 512 KB) ? 16 : 0;
+    return srcSize + (srcSize >> 8) + margin;
+}
 
 
 /*-*************************************