diff --git a/lib/dictBuilder/cover.c b/lib/dictBuilder/cover.c
index 5fd2c9c7..176c386c 100644
--- a/lib/dictBuilder/cover.c
+++ b/lib/dictBuilder/cover.c
@@ -223,10 +223,10 @@ static COVER_ctx_t *g_ctx = NULL;
 /**
  * Returns the sum of the sample sizes.
  */
-static size_t COVER_sum(const size_t *samplesSizes, unsigned firstSample, unsigned lastSample) {
+static size_t COVER_sum(const size_t *samplesSizes, unsigned nbSamples) {
   size_t sum = 0;
   unsigned i;
-  for (i = firstSample; i < lastSample; ++i) {
+  for (i = 0; i < nbSamples; ++i) {
     sum += samplesSizes[i];
   }
   return sum;
@@ -540,13 +540,12 @@ static int COVER_ctx_init(COVER_ctx_t *ctx, const void *samplesBuffer,
                           const size_t *samplesSizes, unsigned nbSamples,
                           unsigned d, double splitPoint) {
   const BYTE *const samples = (const BYTE *)samplesBuffer;
-  const unsigned kFirst = 0;
-  const size_t totalSamplesSize = COVER_sum(samplesSizes, kFirst, nbSamples);
+  const size_t totalSamplesSize = COVER_sum(samplesSizes, nbSamples);
   /* Split samples into testing and training sets */
   const unsigned nbTrainSamples = splitPoint < 1.0 ? (unsigned)((double)nbSamples * splitPoint) : nbSamples;
   const unsigned nbTestSamples = splitPoint < 1.0 ? nbSamples - nbTrainSamples : nbSamples;
-  const size_t trainingSamplesSize = splitPoint < 1.0 ? COVER_sum(samplesSizes, kFirst, nbTrainSamples) : totalSamplesSize;
-  const size_t testSamplesSize = splitPoint < 1.0 ? COVER_sum(samplesSizes, nbTrainSamples, nbSamples) : totalSamplesSize;
+  const size_t trainingSamplesSize = splitPoint < 1.0 ? COVER_sum(samplesSizes, nbTrainSamples) : totalSamplesSize;
+  const size_t testSamplesSize = splitPoint < 1.0 ? COVER_sum(samplesSizes + nbTrainSamples, nbTestSamples) : totalSamplesSize;
   /* Checks */
   if (totalSamplesSize < MAX(d, sizeof(U64)) ||
       totalSamplesSize >= (size_t)COVER_MAX_SAMPLES_SIZE) {
@@ -564,11 +563,6 @@ static int COVER_ctx_init(COVER_ctx_t *ctx, const void *samplesBuffer,
     DISPLAYLEVEL(1, "Total number of testing samples is %u and is invalid.", nbTestSamples);
     return 0;
   }
-  /* Check if nbTrainSamples plus nbTestSamples add up to nbSamples when splitPoint is less than 1*/
-  if (nbTrainSamples + nbTestSamples != nbSamples && splitPoint < 1.0) {
-    DISPLAYLEVEL(1, "nbTrainSamples plus nbTestSamples don't add up to nbSamples");
-    return 0;
-  }
   /* Zero the context */
   memset(ctx, 0, sizeof(*ctx));
   DISPLAYLEVEL(2, "Training on %u samples of total size %u\n", nbTrainSamples,
@@ -976,7 +970,7 @@ ZDICTLIB_API size_t ZDICT_optimizeTrainFromBuffer_cover(
   /* constants */
   const unsigned nbThreads = parameters->nbThreads;
   const double splitPoint =
-      (parameters->splitPoint <= 0.0 || parameters->splitPoint > 1.0) ? DEFAULT_SPLITPOINT : parameters->splitPoint;
+      parameters->splitPoint <= 0.0 ? DEFAULT_SPLITPOINT : parameters->splitPoint;
   const unsigned kMinD = parameters->d == 0 ? 6 : parameters->d;
   const unsigned kMaxD = parameters->d == 0 ? 8 : parameters->d;
   const unsigned kMinK = parameters->k == 0 ? 50 : parameters->k;
diff --git a/lib/dictBuilder/zdict.h b/lib/dictBuilder/zdict.h
index 45d78b05..8244c3ba 100644
--- a/lib/dictBuilder/zdict.h
+++ b/lib/dictBuilder/zdict.h
@@ -86,7 +86,7 @@ typedef struct {
     unsigned d;                  /* dmer size : constraint: 0 < d <= k : Reasonable range [6, 16] */
     unsigned steps;              /* Number of steps : Only used for optimization : 0 means default (32) : Higher means more parameters checked */
     unsigned nbThreads;          /* Number of threads : constraint: 0 < nbThreads : 1 means single-threaded : Only used for optimization : Ignored if ZSTD_MULTITHREAD is not defined */
-    double splitPoint;           /* Percentage of samples used for training: the first nbSamples * splitPoint samples will be used to training */
+    double splitPoint;           /* Percentage of samples used for training: the first nbSamples * splitPoint samples will be used to training, 0 means default (0.8) */
     ZDICT_params_t zParams;
 } ZDICT_cover_params_t;