diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index db672da04..8377b37e5 100644
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -339,6 +339,8 @@ size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, unsigned v
         if (value > 1) return ERROR(compressionParameter_unsupported);
 #endif
         if ((value>1) && (cctx->nbThreads != value)) {
+            if (cctx->staticSize)  /* MT not compatible with static alloc */
+                return ERROR(compressionParameter_unsupported);
             ZSTDMT_freeCCtx(cctx->mtctx);
             cctx->nbThreads = value;
             cctx->mtctx = ZSTDMT_createCCtx(value);
diff --git a/lib/zstd.h b/lib/zstd.h
index 357af9194..eb72fc4e5 100644
--- a/lib/zstd.h
+++ b/lib/zstd.h
@@ -68,7 +68,7 @@ ZSTDLIB_API unsigned ZSTD_versionNumber(void);   /**< to be used when checking d
 #define ZSTD_QUOTE(str) #str
 #define ZSTD_EXPAND_AND_QUOTE(str) ZSTD_QUOTE(str)
 #define ZSTD_VERSION_STRING ZSTD_EXPAND_AND_QUOTE(ZSTD_LIB_VERSION)
-ZSTDLIB_API const char* ZSTD_versionString(void);
+ZSTDLIB_API const char* ZSTD_versionString(void);   /* v1.3.0 */
 
 
 /***************************************
@@ -424,6 +424,7 @@ typedef struct { ZSTD_allocFunction customAlloc; ZSTD_freeFunction customFree; v
 /* use this constant to defer to stdlib's functions */
 static const ZSTD_customMem ZSTD_defaultCMem = { NULL, NULL, NULL};
 
+
 /***************************************
 *  Frame size functions
 ***************************************/