diff --git a/xs/src/libslic3r/GCode.cpp b/xs/src/libslic3r/GCode.cpp
index 308b1ea046..261c8e59d7 100644
--- a/xs/src/libslic3r/GCode.cpp
+++ b/xs/src/libslic3r/GCode.cpp
@@ -1012,9 +1012,10 @@ void GCode::print_machine_envelope(FILE *file, Print &print)
             int(print.config.machine_max_feedrate_y.values.front() + 0.5),
             int(print.config.machine_max_feedrate_z.values.front() + 0.5),
             int(print.config.machine_max_feedrate_e.values.front() + 0.5));
-        fprintf(file, "M204 S%d T%d ; sets acceleration (S) and retract acceleration (T), mm/sec^2\n",
+        fprintf(file, "M204 P%d R%d T%d ; sets acceleration (P, T) and retract acceleration (R), mm/sec^2\n",
             int(print.config.machine_max_acceleration_extruding.values.front() + 0.5),
-            int(print.config.machine_max_acceleration_retracting.values.front() + 0.5));
+            int(print.config.machine_max_acceleration_retracting.values.front() + 0.5),
+            int(print.config.machine_max_acceleration_extruding.values.front() + 0.5));
         fprintf(file, "M205 X%.2lf Y%.2lf Z%.2lf E%.2lf ; sets the jerk limits, mm/sec\n",
             print.config.machine_max_jerk_x.values.front(),
             print.config.machine_max_jerk_y.values.front(),
diff --git a/xs/src/libslic3r/GCodeTimeEstimator.cpp b/xs/src/libslic3r/GCodeTimeEstimator.cpp
index 5543b5cc99..749aac88b3 100644
--- a/xs/src/libslic3r/GCodeTimeEstimator.cpp
+++ b/xs/src/libslic3r/GCodeTimeEstimator.cpp
@@ -1164,11 +1164,25 @@ namespace Slic3r {
     {
         PROFILE_FUNC();
         float value;
-        if (line.has_value('S', value))
+        if (line.has_value('S', value)) {
+            // Legacy acceleration format. This format is used by the legacy Marlin, MK2 or MK3 firmware,
+            // and it is also generated by Slic3r to control acceleration per extrusion type
+            // (there is a separate acceleration settings in Slicer for perimeter, first layer etc).
             set_acceleration(value);
-
-        if (line.has_value('T', value))
-            set_retract_acceleration(value);
+            if (line.has_value('T', value))
+                set_retract_acceleration(value);
+        } else {
+            // New acceleration format, compatible with the upstream Marlin.
+            if (line.has_value('P', value))
+                set_acceleration(value);
+            if (line.has_value('R', value))
+                set_retract_acceleration(value);
+            if (line.has_value('T', value)) {
+                // Interpret the T value as the travel acceleration in the new Marlin format.
+                //FIXME Prusa3D firmware currently does not support travel acceleration value independent from the extruding acceleration value.
+                // set_travel_acceleration(value);
+            }
+        }
     }
 
     void GCodeTimeEstimator::_processM205(const GCodeReader::GCodeLine& line)