diff --git a/lib/decompress/zstd_decompress.c b/lib/decompress/zstd_decompress.c
index 1770476a6..3c51db439 100644
--- a/lib/decompress/zstd_decompress.c
+++ b/lib/decompress/zstd_decompress.c
@@ -111,6 +111,7 @@ static void ZSTD_initDCtx_internal(ZSTD_DCtx* dctx)
     dctx->legacyContext = NULL;
     dctx->previousLegacyVersion = 0;
     dctx->noForwardProgress = 0;
+    dctx->oversizedDuration = 0;
     dctx->bmi2 = ZSTD_cpuid_bmi2(ZSTD_cpuid());
 }
 
diff --git a/lib/decompress/zstd_decompress_internal.h b/lib/decompress/zstd_decompress_internal.h
index 059c81940..68c313811 100644
--- a/lib/decompress/zstd_decompress_internal.h
+++ b/lib/decompress/zstd_decompress_internal.h
@@ -95,6 +95,9 @@ typedef enum {
     ZSTD_use_once = 1            /* Use the dictionary once and set to ZSTD_dont_use */
 } ZSTD_dictUses_e;
 
+#define ZSTD_OVERSIZED_MAXDURATION 128
+#define ZSTD_OVERSIZED_FACTOR 3
+
 struct ZSTD_DCtx_s
 {
     const ZSTD_seqSymbol* LLTptr;
@@ -151,6 +154,8 @@ struct ZSTD_DCtx_s
     /* workspace */
     BYTE litBuffer[ZSTD_BLOCKSIZE_MAX + WILDCOPY_OVERLENGTH];
     BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX];
+
+    size_t oversizedDuration;
 };  /* typedef'd to ZSTD_DCtx within "zstd.h" */