diff --git a/src/libslic3r/Preset.cpp b/src/libslic3r/Preset.cpp
index 846cdb3881a..4aecc7fc6ab 100644
--- a/src/libslic3r/Preset.cpp
+++ b/src/libslic3r/Preset.cpp
@@ -2235,6 +2235,14 @@ const std::string& ExtruderFilaments::get_preset_name_by_alias(const std::string
     return alias;
 }
 
+void ExtruderFilaments::select_filament(size_t idx) 
+{ 
+    assert(idx == size_t(-1) || idx < m_extr_filaments.size());
+    // Check idx befor saving it's value to m_idx_selected.
+    // Invalidate m_idx_selected, if idx is out of range m_extr_filaments
+    m_idx_selected = (idx == size_t(-1) || idx < m_extr_filaments.size()) ? idx : size_t(-1); 
+}
+
 bool ExtruderFilaments::select_filament(const std::string &name_w_suffix, bool force/*= false*/)
 {
     std::string name = Preset::remove_suffix_modified(name_w_suffix);
diff --git a/src/libslic3r/Preset.hpp b/src/libslic3r/Preset.hpp
index 533c6938128..589be92a281 100644
--- a/src/libslic3r/Preset.hpp
+++ b/src/libslic3r/Preset.hpp
@@ -906,7 +906,7 @@ class ExtruderFilaments
     // Select filament by the full filament name, which contains name of filament, separator and name of selected preset
     // If full_name doesn't contain name of selected preset, then select first preset in the list for this filament
     bool select_filament(const std::string& name, bool force = false);
-    void select_filament(size_t idx)                        { m_idx_selected = idx; }
+    void select_filament(size_t idx);
 
     std::string             get_selected_preset_name()  const { return m_idx_selected == size_t(-1) ? std::string() : m_extr_filaments[m_idx_selected].preset->name; }
     const Preset*           get_selected_preset()       const { return m_idx_selected == size_t(-1) ? nullptr   : m_extr_filaments[m_idx_selected].preset; }