diff --git a/src/PrusaSlicer.cpp b/src/PrusaSlicer.cpp
index 0a22305ec..f7350dace 100644
--- a/src/PrusaSlicer.cpp
+++ b/src/PrusaSlicer.cpp
@@ -484,6 +484,12 @@ int CLI::run(int argc, char **argv)
                 if (printer_technology == ptFFF) {
                     for (auto* mo : model.objects)
                         fff_print.auto_assign_extruders(mo);
+                } else {
+                    // The default for "output_filename_format" is good for FDM: "[input_filename_base].gcode"
+                    // Replace it with a reasonable SLA default.
+                    std::string &format = m_print_config.opt_string("output_filename_format", true);
+                    if (format == static_cast<const ConfigOptionString*>(m_print_config.def()->get("output_filename_format")->default_value.get())->value)
+                        format = "[input_filename_base].SL1";
                 }
                 print->apply(model, m_print_config);
                 std::string err = print->validate();
diff --git a/src/libslic3r/GCode/PostProcessor.cpp b/src/libslic3r/GCode/PostProcessor.cpp
index e3131d591..9a66e743b 100644
--- a/src/libslic3r/GCode/PostProcessor.cpp
+++ b/src/libslic3r/GCode/PostProcessor.cpp
@@ -182,8 +182,10 @@ namespace Slic3r {
 void run_post_process_scripts(const std::string &path, const DynamicPrintConfig &config)
 {
     const auto* post_process = config.opt<ConfigOptionStrings>("post_process");
-    assert(post_process);
-    if (post_process->values.empty())
+    if (// likely running in SLA mode
+        post_process == nullptr || 
+        // no post-processing script
+        post_process->values.empty())
         return;
 
     // Store print configuration into environment variables.