diff --git a/src/ext/spout/SpoutBuilder.php b/src/ext/spout/SpoutBuilder.php
index f77bb80..61da982 100644
--- a/src/ext/spout/SpoutBuilder.php
+++ b/src/ext/spout/SpoutBuilder.php
@@ -241,6 +241,8 @@ class SpoutBuilder extends AbstractBuilder {
 
   protected int $rowStyle;
 
+  protected int $currentRow;
+
   protected ?bool $differentOddEven = null;
 
   protected int $oddEvenIndex = 0;
@@ -267,6 +269,7 @@ class SpoutBuilder extends AbstractBuilder {
       $this->built = false;
     }
     $this->rowStyle = self::STYLE_ROW;
+    $this->currentRow = 1;
 
     switch ($this->ssType) {
     case self::SS_TYPE_ODS:
@@ -367,7 +370,9 @@ class SpoutBuilder extends AbstractBuilder {
   function _write(array $row, ?array $colStyles=null, ?array $rowStyle=null): void {
     $rowParams = null;
     if ($rowStyle !== null) {
-      foreach (array_keys(ref_builder::ROW) as $method) {
+      # séparer rowParams (pour configurer l'instance de $row) et $rowStyle
+      # (pour appliquer un style sur la ligne)
+      foreach (array_keys(ref_builder::ROW_PARAMS) as $method) {
         $value = $rowStyle[$method] ?? null;
         unset($rowStyle[$method]);
         if ($value !== null) $rowParams[$method] = $value;
@@ -398,6 +403,7 @@ class SpoutBuilder extends AbstractBuilder {
       $cell->setType($type);
       $cells[] = $cell;
     }
+
     if ($this->rowStyle === self::STYLE_HEADER) {
       $rowStyle ??= $headerStyle;
     } elseif ($differentOddEven && $this->oddEvenIndex % 2 == 0) {
@@ -406,7 +412,16 @@ class SpoutBuilder extends AbstractBuilder {
     $rowStyle ??= $oddStyle;
     self::ensure_style($rowStyle);
     $row = WriterEntityFactory::createRow($cells, $rowStyle);
-    self::apply_params($row, $rowParams, ref_builder::ROW);
+    self::apply_params($row, $rowParams, ref_builder::ROW_PARAMS);
+
+    $mergeCells = $rowParams["merge_cells"] ?? null;
+    if ($mergeCells !== null) {
+      foreach ($mergeCells as [$leftCol, $rightCol]) {
+        $this->mergeCells($leftCol, $this->currentRow, $rightCol, $this->currentRow);
+
+      }
+    }
+
     $this->ssWriter->addRow($row);
     if ($differentOddEven) $this->oddEvenIndex++;
   }
diff --git a/src/ref/ext/spout/ref_builder.php b/src/ref/ext/spout/ref_builder.php
index 11ff081..21b1fbf 100644
--- a/src/ref/ext/spout/ref_builder.php
+++ b/src/ref/ext/spout/ref_builder.php
@@ -45,8 +45,9 @@ class ref_builder {
 
   const PARAMS_SHEET_VIEW = [];
 
-  const ROW = [
+  const ROW_PARAMS = [
     "->setHeight" => ["float"],
+    "merge_cells" => "array",
   ];
 
   const COLORS = [