diff --git a/src/libslic3r/GCode/ToolOrdering.cpp b/src/libslic3r/GCode/ToolOrdering.cpp
index ee03d6e959..65c887f343 100644
--- a/src/libslic3r/GCode/ToolOrdering.cpp
+++ b/src/libslic3r/GCode/ToolOrdering.cpp
@@ -138,7 +138,8 @@ static double calc_max_layer_height(const PrintConfig &config, double max_object
 {
     double max_layer_height = std::numeric_limits<double>::max();
     for (size_t i = 0; i < config.nozzle_diameter.values.size(); ++ i) {
-        double mlh = config.max_layer_height.values[i];
+        // max_layer_height may be shorter than the extruder count; get_at() clamps.
+        double mlh = config.max_layer_height.get_at(i);
         if (mlh == 0.)
             mlh = 0.75 * config.nozzle_diameter.values[i];
         max_layer_height = std::min(max_layer_height, mlh);
diff --git a/tests/fff_print/test_multifilament.cpp b/tests/fff_print/test_multifilament.cpp
index 12c1cae766..f33a8e1e61 100644
--- a/tests/fff_print/test_multifilament.cpp
+++ b/tests/fff_print/test_multifilament.cpp
@@ -85,3 +85,22 @@ TEST_CASE("Per-object wall filament override is honored", "[MultiFilament]")
     CHECK(tools_for_role(gcode, "perimeter") == std::set<int>{ 0, 1 });
     CHECK(tools_for_role(gcode, "infill")    == std::set<int>{ 0 }); // infill not overridden: stays on F1
 }
+
+// max_layer_height can be shorter than the extruder count (normalization sizes it to the
+// filament count under single_extruder_multi_material). calc_max_layer_height() in ToolOrdering
+// indexed it per-nozzle and read past the end. Shortened directly here to isolate that read;
+// the other per-extruder keys stay extruder-length so slicing reaches the code under test.
+TEST_CASE("Multi-extruder slice stays in bounds with a short max_layer_height", "[MultiFilament]")
+{
+    DynamicPrintConfig config = multifilament_config(2);
+    config.set_deserialize_strict({
+        { "nozzle_diameter",           "0.4,0.4" },
+        { "printer_extruder_id",       "1,2" },
+        { "printer_extruder_variant",  "Direct Drive Standard,Direct Drive Standard" },
+        { "extruder_printable_height", "0,0" },
+        { "max_layer_height",          "0.3" }, // deliberately one entry short
+    });
+    Print print;
+    init_and_process_print({ cube(20) }, print, config);
+    REQUIRE_FALSE(print.objects().front()->layers().empty());
+}