diff --git a/src/libslic3r/GCode.cpp b/src/libslic3r/GCode.cpp
index 744484765b..db958482c7 100644
--- a/src/libslic3r/GCode.cpp
+++ b/src/libslic3r/GCode.cpp
@@ -7971,7 +7971,23 @@ std::string GCode::set_extruder(unsigned int new_filament_id, double print_z, bo
 
     // If ooze prevention is enabled, park current extruder in the nearest
     // standby point and set it to the standby temperature.
-    if (m_ooze_prevention.enable && m_writer.filament() != nullptr)
+    //
+    // Same-physical short-circuit: skip the standby cool-down when the old and
+    // new filament both route to the same physical extruder via
+    // physical_extruder_map (AFC/MMU lane swaps where the active heater stays
+    // selected, just a different lane is loaded). The cool-down → re-heat
+    // round trip is pointless in that case — same nozzle, same heater, just a
+    // different filament feeding it. post_toolchange below still emits M109
+    // to the new filament's print temp, so per-lane temperature differences
+    // (e.g. PLA lane → PETG lane on the same AFC manifold) are still handled.
+    auto same_physical_extruder = [&](int a, int b) {
+        const auto& pem = m_config.physical_extruder_map.values;
+        return !pem.empty() && a >= 0 && b >= 0
+            && a < (int)pem.size() && b < (int)pem.size()
+            && pem[a] == pem[b];
+    };
+    if (m_ooze_prevention.enable && m_writer.filament() != nullptr
+        && !same_physical_extruder(m_writer.filament()->id(), (int)new_filament_id))
         gcode += m_ooze_prevention.pre_toolchange(*this);
 
     // BBS