diff --git a/src/string_utils.h b/src/string_utils.h
index e0dc1ce..a638296 100644
--- a/src/string_utils.h
+++ b/src/string_utils.h
@@ -78,29 +78,17 @@ static std::string itox(T i) {
     return ss.str();
 }
 
-static bool try_stoi(int& val, const std::string& str, std::size_t* pos = 0, int base = 10)
+static bool try_stoi(int& val, const std::string& str)
 {
-    try {
-        val = std::stoi(str, pos, base);
+    if (sscanf(str.c_str(), "%d", &val) == 1)
         return true;
-    } catch (std::invalid_argument& e) {
-#ifndef NDEBUG
-        std::cerr << __func__ << ": invalid argument: '" << str << "'" << std::endl;
-#endif
-    }
     return false;
 }
 
-static bool try_stoull(unsigned long long& val, const std::string& str, std::size_t* pos = 0, int base = 10)
+static bool try_stoull(unsigned long long& val, const std::string& str)
 {
-    try {
-        val = std::stoull(str, pos, base);
+    if (sscanf(str.c_str(), "%llu", &val) == 1)
         return true;
-    } catch (std::invalid_argument& e) {
-#ifndef NDEBUG
-        std::cerr << __func__ << ": invalid argument: '" << str << "'" << std::endl;
-#endif
-    }
     return false;
 }