--- a/xs/src/libslic3r/Config.hpp	2015-06-17 04:38:28.000000000 -0400
+++ b/xs/src/libslic3r/Config.hpp	2017-09-27 10:59:26.527103728 -0400
@@ -65,7 +65,7 @@
     
     bool deserialize(std::string str) {
         std::istringstream iss(str);
-        return iss >> this->value;
+        return static_cast<bool>(iss >> this->value);
     };
 };
 
@@ -124,7 +124,7 @@
     
     bool deserialize(std::string str) {
         std::istringstream iss(str);
-        return iss >> this->value;
+        return static_cast<bool>(iss >> this->value);
     };
 };
 
@@ -249,7 +249,7 @@
     bool deserialize(std::string str) {
         // don't try to parse the trailing % since it's optional
         std::istringstream iss(str);
-        return iss >> this->value;
+        return static_cast<bool>(iss >> this->value);
     };
 };
 
@@ -279,7 +279,7 @@
     bool deserialize(std::string str) {
         this->percent = str.find_first_of("%") != std::string::npos;
         std::istringstream iss(str);
-        return iss >> this->value;
+        return static_cast<bool>(iss >> this->value);
     };
 };