diff --git a/NEWS b/NEWS
index 2667ba43..e9f5b78d 100644
--- a/NEWS
+++ b/NEWS
@@ -4,6 +4,7 @@ fix  : `LZ4_compress_fast_continue()` produced wrong data when a block overwrote
 fix  : `LZ4_compress_destSize_extState()` corrupted data with `acceleration <= 0`, and could read out of bounds (since v1.10.0)
 fix  : negative sizes crashed `LZ4_decompress_safe_partial()` (since v1.9.3) and `LZ4_decompress_fast()` (since v1.9.4)
 fix  : `LZ4_saveDict()` with a negative `dictSize` copied up to 64 KB into `safeBuffer`, by @arthuz-th
+fix  : `LZ4_saveDictHC()` before any compression (new or reset stream) corrupted the next compressed block
 fix  : `LZ4_decompress_safe_partial()` could leave previous `dst` content in decoded data with an invalid offset 0 (since v1.8.3)
 fix  : heap overflow with an invalid `blockSizeID` in `LZ4F_compressBegin()` and `LZ4F_writeOpen()`, by @jaypatrickhoward
 fix  : `LZ4F_compressBegin()` failing on allocation left an inconsistent frame in progress : it is now invalidated
diff --git a/lib/lz4hc.c b/lib/lz4hc.c
index 6fd6e7e4..a98bb881 100644
--- a/lib/lz4hc.c
+++ b/lib/lz4hc.c
@@ -1793,6 +1793,9 @@ int LZ4_saveDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, char* safeBuffer, int dictS
     LZ4HC_CCtx_internal* const streamPtr = &LZ4_streamHCPtr->internal_donotuse;
     int const prefixSize = (int)(streamPtr->end - streamPtr->prefixStart);
     DEBUGLOG(5, "LZ4_saveDictHC(%p, %p, %d)", LZ4_streamHCPtr, safeBuffer, dictSize);
+    /* nothing compressed yet (new or reset stream) : nothing to save,
+     * the stream remains to be initialized by next compression (attached dictionary included) */
+    if (streamPtr->prefixStart == NULL) return 0;
     assert(prefixSize >= 0);
     if (dictSize > 64 KB) dictSize = 64 KB;
     if (dictSize < 4) dictSize = 0;
diff --git a/tests/fuzzer.c b/tests/fuzzer.c
index 1daedd3e..fafc099d 100644
--- a/tests/fuzzer.c
+++ b/tests/fuzzer.c
@@ -1747,6 +1747,34 @@ static void FUZ_unitTests(int compressionLevel)
             {   char tmp_buffer[240] = { 0 };
                 FUZ_CHECKTEST( LZ4_saveDictHC(ctx, tmp_buffer, sizeof(tmp_buffer)) != 0,
                 "LZ4_saveDictHC() can't save anything since compression hasn't started");
+            }
+
+            /* next block is compressed as the first one of the stream,
+             * without (attach==0) or with (attach==1) an attached dictionary */
+            {   LZ4_streamHC_t* const dictHC = LZ4_createStreamHC();
+                int const levels[] = { LZ4HC_CLEVEL_DEFAULT, 3, LZ4HC_CLEVEL_OPT_MIN, LZ4HC_CLEVEL_MAX };   /* first : level of LZ4_initStreamHC() */
+                int attach, l;
+                FUZ_CHECKTEST(dictHC == NULL, "LZ4_createStreamHC() allocation failed");
+                for (l = 0; l < (int)(sizeof(levels) / sizeof(levels[0])); l++) {
+                    for (attach = 0; attach <= 1; attach++) {
+                        char saveBuffer[240];
+                        int cSize, dSize;
+                        if (l || attach) LZ4_resetStreamHC_fast(ctx, levels[l]);   /* first test : right after init */
+                        if (attach) {
+                            LZ4_resetStreamHC_fast(dictHC, levels[l]);
+                            FUZ_CHECKTEST(LZ4_loadDictHC(dictHC, testInput, 64 KB) != 64 KB, "LZ4_loadDictHC() failed");
+                            LZ4_attach_HC_dictionary(ctx, dictHC);
+                        }
+                        FUZ_CHECKTEST( LZ4_saveDictHC(ctx, saveBuffer, sizeof(saveBuffer)) != 0,
+                        "LZ4_saveDictHC() can't save anything since compression hasn't started");
+                        cSize = LZ4_compress_HC_continue(ctx, testInput + 64 KB, testCompressed, 64 KB, testCompressedSize);
+                        FUZ_CHECKTEST(cSize <= 0, "LZ4_compress_HC_continue() failed");
+                        dSize = LZ4_decompress_safe_usingDict(testCompressed, testVerify, cSize, 64 KB,
+                                                              testInput, attach ? 64 KB : 0);
+                        FUZ_CHECKTEST(dSize != 64 KB || memcmp(testVerify, testInput + 64 KB, 64 KB),
+                        "level %i, dictionary %i : block compressed after LZ4_saveDictHC() is corrupted", levels[l], attach);
+                }   }
+                LZ4_freeStreamHC(dictHC);
         }   }
         DISPLAYLEVEL(3, "OK \n");