diff --git a/xs/src/libslic3r/PrintGCode.cpp b/xs/src/libslic3r/PrintGCode.cpp
index efbf6208e..bf9b85dda 100644
--- a/xs/src/libslic3r/PrintGCode.cpp
+++ b/xs/src/libslic3r/PrintGCode.cpp
@@ -110,8 +110,6 @@ PrintGCode::output()
     }
 
     // set bed temperature
-    auto bed_temp_regex { std::regex("M(?:190|140)", std::regex_constants::icase)};
-    auto ex_temp_regex { std::regex("M(?:109|104)", std::regex_constants::icase)};
     auto temp{config.first_layer_bed_temperature.getFloat()};
     if (config.has_heatbed && temp > 0 && std::regex_search(config.start_gcode.getString(), bed_temp_regex)) {
         fh << gcodegen.writer.set_bed_temperature(temp, 1);
diff --git a/xs/src/libslic3r/PrintGCode.hpp b/xs/src/libslic3r/PrintGCode.hpp
index 1160ce21f..0001c8b70 100644
--- a/xs/src/libslic3r/PrintGCode.hpp
+++ b/xs/src/libslic3r/PrintGCode.hpp
@@ -12,6 +12,7 @@
 
 #include <string>
 #include <iostream>
+#include <regex>
 
 namespace Slic3r {
 
@@ -66,6 +67,11 @@ private:
 
     // Chain the paths hierarchically by a greedy algorithm to minimize a travel distance.
     std::string _extrude_infill(std::map<size_t,ExtrusionEntityCollection> &by_region);
+
+    /// regular expression to match heater gcodes
+    std::regex bed_temp_regex { std::regex("M(?:190|140)", std::regex_constants::icase)};
+    /// regular expression to match heater gcodes
+    std::regex ex_temp_regex { std::regex("M(?:109|104)", std::regex_constants::icase)};
 };
 
 } // namespace Slic3r