diff --git a/lib/zstd.c b/lib/zstd.c
index db533f9a5..776a5bca5 100644
--- a/lib/zstd.c
+++ b/lib/zstd.c
@@ -120,8 +120,6 @@
 #define GB *(1U<<30)
 
 #define BLOCKSIZE (128 KB)                 /* define, for static allocation */
-#define MIN_SEQUENCES_SIZE (2 /*seqNb*/ + 2 /*dumps*/ + 3 /*seqTables*/ + 1 /*bitStream*/)
-#define MIN_CBLOCK_SIZE (3 /*litCSize*/ + MIN_SEQUENCES_SIZE)
 #define IS_RAW BIT0
 #define IS_RLE BIT1
 
diff --git a/lib/zstd_internal.h b/lib/zstd_internal.h
index f63636459..ee0f67359 100644
--- a/lib/zstd_internal.h
+++ b/lib/zstd_internal.h
@@ -214,6 +214,10 @@ void ZSTD_resetSeqStore(seqStore_t* ssPtr);
 #define MaxLL  ((1<<LLbits) - 1)
 #define MaxOff   31
 
+#define MIN_SEQUENCES_SIZE (2 /*seqNb*/ + 2 /*dumps*/ + 3 /*seqTables*/ + 1 /*bitStream*/)
+#define MIN_CBLOCK_SIZE (3 /*litCSize*/ + MIN_SEQUENCES_SIZE)
+
+
 /** ZSTD_storeSeq
     Store a sequence (literal length, literals, offset code and match length) into seqStore_t
     @offsetCode : distance to match, or 0 == repCode
diff --git a/lib/zstdhc.c b/lib/zstdhc.c
index ccd252362..fb10b4b10 100644
--- a/lib/zstdhc.c
+++ b/lib/zstdhc.c
@@ -953,7 +953,7 @@ static size_t ZSTD_HC_compress_generic (ZSTD_HC_CCtx* ctxPtr,
     {
         size_t cSize;
 
-        if (maxDstSize < 5) return ERROR(dstSize_tooSmall);   /* not enough space to store compressed block */
+        if (maxDstSize < 3 + MIN_CBLOCK_SIZE) return ERROR(dstSize_tooSmall);   /* not enough space to store compressed block */
 
         if (remaining < blockSize) blockSize = remaining;
         cSize = blockCompressor(ctxPtr, op+3, maxDstSize-3, ip, blockSize);