diff --git a/src/libslic3r/GCode.cpp b/src/libslic3r/GCode.cpp
index aef83f21f..1f7eaba24 100644
--- a/src/libslic3r/GCode.cpp
+++ b/src/libslic3r/GCode.cpp
@@ -35,6 +35,8 @@
 #include "SVG.hpp"
 
 #include <tbb/parallel_for.h>
+#include <tbb/task_scheduler_observer.h>
+#include <tbb/enumerable_thread_specific.h>
 
 // Intel redesigned some TBB interface considerably when merging TBB with their oneAPI set of libraries, see GH #7332.
 // We are using quite an old TBB 2017 U7. Before we update our build servers, let's use the old API, which is deprecated in up to date TBB.
@@ -1488,6 +1490,32 @@ void GCode::_do_export(Print& print, GCodeOutputStream &file, ThumbnailsGenerato
     print.throw_if_canceled();
 }
 
+// For unknown reasons and in sporadic cases when GCode export is processing, some participating thread
+// in tbb::parallel_pipeline has not set locales to "C", probably because this thread is newly spawned.
+// So in this class method on_scheduler_entry is called for every thread before it starts participating
+// in tbb::parallel_pipeline to ensure that locales are set correctly
+
+// For tbb::parallel_pipeline, it seems that on_scheduler_entry is called for every layer and every filter.
+// We ensure using thread-local storage that locales will be set to "C" just once for any participating thread.
+class TBBLocalesSetter : public tbb::task_scheduler_observer
+{
+public:
+    TBBLocalesSetter() { this->observe(true); }
+    ~TBBLocalesSetter() override = default;
+
+    void on_scheduler_entry(bool is_worker) override
+    {
+        if (bool &is_locales_sets = m_is_locales_sets.local(); !is_locales_sets) {
+            // Set locales of the worker thread to "C".
+            set_c_locales();
+            is_locales_sets = true;
+        }
+    }
+
+private:
+    tbb::enumerable_thread_specific<bool, tbb::cache_aligned_allocator<bool>, tbb::ets_key_usage_type::ets_key_per_instance> m_is_locales_sets;
+};
+
 // Process all layers of all objects (non-sequential mode) with a parallel pipeline:
 // Generate G-code, run the filters (vase mode, cooling buffer), run the G-code analyser
 // and export G-code into file.
@@ -1531,6 +1559,10 @@ void GCode::process_layers(
         [&output_stream](std::string s) { output_stream.write(s); }
     );
 
+    // It registers a handler that sets locales to "C" before any TBB thread starts participating in tbb::parallel_pipeline.
+    // Handler is unregistered when the destructor is called.
+    TBBLocalesSetter locales_setter;
+
     // The pipeline elements are joined using const references, thus no copying is performed.
     output_stream.find_replace_supress();
     if (m_spiral_vase && m_find_replace)
@@ -1584,6 +1616,10 @@ void GCode::process_layers(
         [&output_stream](std::string s) { output_stream.write(s); }
     );
 
+    // It registers a handler that sets locales to "C" before any TBB thread starts participating in tbb::parallel_pipeline.
+    // Handler is unregistered when the destructor is called.
+    TBBLocalesSetter locales_setter;
+
     // The pipeline elements are joined using const references, thus no copying is performed.
     output_stream.find_replace_supress();
     if (m_spiral_vase && m_find_replace)
diff --git a/src/libslic3r/LocalesUtils.hpp b/src/libslic3r/LocalesUtils.hpp
index f63c3572f..ce8030ceb 100644
--- a/src/libslic3r/LocalesUtils.hpp
+++ b/src/libslic3r/LocalesUtils.hpp
@@ -43,6 +43,25 @@ std::string float_to_string_decimal_point(double value, int precision = -1);
 //std::string float_to_string_decimal_point(float value,  int precision = -1);
 double string_to_double_decimal_point(const std::string_view str, size_t* pos = nullptr);
 
+// Set locales to "C".
+inline void set_c_locales()
+{
+#ifdef _WIN32
+    _configthreadlocale(_ENABLE_PER_THREAD_LOCALE);
+    std::setlocale(LC_ALL, "C");
+#else
+    // We are leaking some memory here, because the newlocale() produced memory will never be released.
+    // This is not a problem though, as there will be a maximum one worker thread created per physical thread.
+    uselocale(newlocale(
+#ifdef __APPLE__
+        LC_ALL_MASK
+#else // some Unix / Linux / BSD
+        LC_ALL
+#endif
+        , "C", nullptr));
+#endif
+}
+
 } // namespace Slic3r
 
 #endif // slic3r_LocalesUtils_hpp_
diff --git a/src/libslic3r/Thread.cpp b/src/libslic3r/Thread.cpp
index 4e7bd073a..c099f8de6 100644
--- a/src/libslic3r/Thread.cpp
+++ b/src/libslic3r/Thread.cpp
@@ -15,6 +15,7 @@
 
 #include "Thread.hpp"
 #include "Utils.hpp"
+#include "LocalesUtils.hpp"
 
 namespace Slic3r {
 
@@ -234,21 +235,8 @@ void name_tbb_thread_pool_threads_set_locale()
 				std::ostringstream name;
 		        name << "slic3r_tbb_" << range.begin();
 		        set_current_thread_name(name.str().c_str());
-		        // Set locales of the worker thread to "C".
-#ifdef _WIN32
-			    _configthreadlocale(_ENABLE_PER_THREAD_LOCALE);
-			    std::setlocale(LC_ALL, "C");
-#else
-				// We are leaking some memory here, because the newlocale() produced memory will never be released.
-				// This is not a problem though, as there will be a maximum one worker thread created per physical thread.
-				uselocale(newlocale(
-#ifdef __APPLE__
-					LC_ALL_MASK
-#else // some Unix / Linux / BSD
-					LC_ALL
-#endif
-					, "C", nullptr));
-#endif
+                // Set locales of the worker thread to "C".
+                set_c_locales();
     		}
         });
 }