diff --git a/src/PrusaSlicer.cpp b/src/PrusaSlicer.cpp
index fab1ad5715..5eb3893447 100644
--- a/src/PrusaSlicer.cpp
+++ b/src/PrusaSlicer.cpp
@@ -644,8 +644,10 @@ int CLI::run(int argc, char **argv)
                 sla_print.set_status_callback(
                             [](const PrintBase::SlicingStatus& s)
                 {
-                    if(s.percent >= 0) // FIXME: is this sufficient?
+                    if(s.percent >= 0) { // FIXME: is this sufficient?
                         printf("%3d%s %s\n", s.percent, "% =>", s.text.c_str());
+                        std::fflush(stdout);
+                    }
                 });
 
                 PrintBase  *print = (printer_technology == ptFFF) ? static_cast<PrintBase*>(&fff_print) : static_cast<PrintBase*>(&sla_print);
diff --git a/src/libslic3r/PrintBase.cpp b/src/libslic3r/PrintBase.cpp
index ca13365d15..0254e5cb25 100644
--- a/src/libslic3r/PrintBase.cpp
+++ b/src/libslic3r/PrintBase.cpp
@@ -107,8 +107,10 @@ void PrintBase::status_update_warnings(int step, PrintStateBase::WarningLevel /*
         auto status = print_object ? SlicingStatus(*print_object, step) : SlicingStatus(*this, step);
         m_status_callback(status);
     }
-    else if (! message.empty())
+    else if (! message.empty()) {
         printf("%s warning: %s\n",  print_object ? "print_object" : "print", message.c_str());
+        std::fflush(stdout);
+    }
 }
 
 std::mutex& PrintObjectBase::state_mutex(PrintBase *print)
diff --git a/src/libslic3r/PrintBase.hpp b/src/libslic3r/PrintBase.hpp
index 4b4976ea43..2c113f1ee2 100644
--- a/src/libslic3r/PrintBase.hpp
+++ b/src/libslic3r/PrintBase.hpp
@@ -495,7 +495,7 @@ public:
     // Calls a registered callback to update the status, or print out the default message.
     void                    set_status(int percent, const std::string &message, unsigned int flags = SlicingStatus::DEFAULT) {
 		if (m_status_callback) m_status_callback(SlicingStatus(percent, message, flags));
-        else printf("%d => %s\n", percent, message.c_str());
+        else { printf("%d => %s\n", percent, message.c_str()); std::fflush(stdout); }
     }
 
     typedef std::function<void()>  cancel_callback_type;