diff --git a/tests/fuzzer.c b/tests/fuzzer.c
index f799b5f9..d64b46ba 100644
--- a/tests/fuzzer.c
+++ b/tests/fuzzer.c
@@ -25,6 +25,7 @@
 #include <stdlib.h>       /* free */
 #include <stdio.h>        /* fgets, sscanf */
 #include <string.h>       /* strcmp */
+#include <assert.h>
 #define ZSTD_STATIC_LINKING_ONLY  /* ZSTD_compressContinue, ZSTD_compressBlock */
 #include "zstd.h"         /* ZSTD_VERSION_STRING */
 #include "zstd_errors.h"  /* ZSTD_getErrorCode */
@@ -365,6 +366,23 @@ static int basicUnitTests(U32 seed, double compressibility)
     }
     DISPLAYLEVEL(4, "OK \n");
 
+    DISPLAYLEVEL(4, "test%di : re-use CCtx with expanding block size : ", testNb++);
+    {   ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        ZSTD_parameters const params = ZSTD_getParams(1, ZSTD_CONTENTSIZE_UNKNOWN, 0);
+        assert(params.fParams.contentSizeFlag == 1);  /* block size will be adapted if pledgedSrcSize is enabled */
+        CHECK_Z( ZSTD_compressBegin_advanced(cctx, NULL, 0, params, 1 /*pledgedSrcSize*/) );
+        CHECK_Z( ZSTD_compressEnd(cctx, compressedBuffer, compressedBufferSize, CNBuffer, 1) ); /* creates a block size of 1 */
+
+        CHECK_Z( ZSTD_compressBegin_advanced(cctx, NULL, 0, params, ZSTD_CONTENTSIZE_UNKNOWN) );  /* re-use same parameters */
+        {   size_t const inSize = 2* 128 KB;
+            size_t const outSize = ZSTD_compressBound(inSize);
+            CHECK_Z( ZSTD_compressEnd(cctx, compressedBuffer, outSize, CNBuffer, inSize) );
+            /* will fail if blockSize is not resized */
+        }
+        ZSTD_freeCCtx(cctx);
+    }
+    DISPLAYLEVEL(4, "OK \n");
+
     /* Static CCtx tests */
 #define STATIC_CCTX_LEVEL 3
     DISPLAYLEVEL(4, "test%3i : create static CCtx for level %u :", testNb++, STATIC_CCTX_LEVEL);