diff --git a/src/libs/antares/study/scenario-builder/TSnumberData.cpp b/src/libs/antares/study/scenario-builder/TSnumberData.cpp
index 2b35738421..4616c33c5b 100644
--- a/src/libs/antares/study/scenario-builder/TSnumberData.cpp
+++ b/src/libs/antares/study/scenario-builder/TSnumberData.cpp
@@ -395,8 +395,6 @@ bool thermalTSNumberData::apply(Study& study)
     // WARNING: We may have some thermal clusters with the `mustrun` option
     auto clusterCount = (uint)area.thermal.clusterCount();
 
-    const uint tsGenCountThermal = get_tsGenCount(study);
-
     for (uint clusterIndex = 0; clusterIndex != clusterCount; ++clusterIndex)
     {
         auto& cluster = *(area.thermal.clusters[clusterIndex]);
@@ -404,9 +402,13 @@ bool thermalTSNumberData::apply(Study& study)
         assert(clusterIndex < pTSNumberRules.width);
         const auto& col = pTSNumberRules[clusterIndex];
 
-        logprefix.clear() << "Thermal: Area '" << area.name << "', cluster: '" << cluster.name()
+        uint tsGenCount = cluster.tsGenBehavior == LocalTSGenerationBehavior::forceNoGen ?
+            cluster.series.timeSeries.width : get_tsGenCount(study);
+
+        logprefix.clear() << "Thermal: area '" << area.name << "', cluster: '" << cluster.name()
                           << "': ";
-        ret = ApplyToMatrix(errors, logprefix, *cluster.series, col, tsGenCountThermal) && ret;
+        ret = ApplyToMatrix(errors, logprefix, cluster.series, col, tsGenCount) && ret;
+
     }
     return ret;
 }
diff --git a/src/tests/src/libs/antares/study/scenario-builder/test-sc-builder-file-read-line.cpp b/src/tests/src/libs/antares/study/scenario-builder/test-sc-builder-file-read-line.cpp
index 9268bab171..c262d0195d 100644
--- a/src/tests/src/libs/antares/study/scenario-builder/test-sc-builder-file-read-line.cpp
+++ b/src/tests/src/libs/antares/study/scenario-builder/test-sc-builder-file-read-line.cpp
@@ -386,4 +386,25 @@ BOOST_AUTO_TEST_CASE(on_link_area2_area3_and_on_year_19__ntc_TS_number_6_is_chos
 	BOOST_CHECK_EQUAL(link_23->timeseriesNumbers[0][yearNumber.to<uint>()], tsNumber.to<uint>() - 1);
 }
 
+// ========================
+// Tests on TSNumberData
+// ========================
+BOOST_FIXTURE_TEST_CASE(thermalTSNumberData, Fixture)
+{
+    ScenarioBuilder::thermalTSNumberData tsdata;
+    tsdata.attachArea(area_1);
+    tsdata.reset(*study);
+    tsdata.setTSnumber(thCluster_12.get(), 2, 22);
+    tsdata.setTSnumber(thCluster_12.get(), 5, 32); //out of bounds
+
+    study->parameters.nbTimeSeriesThermal = 1;
+    thCluster_12->tsGenBehavior = LocalTSGenerationBehavior::forceNoGen;
+    thCluster_12->series.timeSeries.resize(30, 8760);
+
+    tsdata.apply(*study);
+
+    BOOST_CHECK_EQUAL(thCluster_12->series.timeseriesNumbers[0][2], 21);
+    BOOST_CHECK_EQUAL(thCluster_12->series.timeseriesNumbers[0][5], 0);
+}
+
 BOOST_AUTO_TEST_SUITE_END()