diff --git a/src/machine/csr/controlstate.h b/src/machine/csr/controlstate.h
index 7f5cde29..90918fd9 100644
--- a/src/machine/csr/controlstate.h
+++ b/src/machine/csr/controlstate.h
@@ -255,16 +255,16 @@ namespace machine { namespace CSR {
 
     class RegisterMapByName {
         bool initialized = false;
-        std::unordered_map<const char *, size_t> map;
+        std::unordered_map<std::string, size_t> map;
 
         void init() {
             for (size_t i = 0; i < REGISTERS.size(); i++) {
-                map.emplace(REGISTERS[i].name, i);
+                map.emplace(std::string(REGISTERS[i].name), i);
             }
             initialized = true;
         }
     public:
-        size_t at(const char* name) {
+        size_t at(std::string name) {
             if (!initialized) init();
             return map.at(name);
         }
diff --git a/src/machine/instruction.cpp b/src/machine/instruction.cpp
index c132096a..f43e1d2b 100644
--- a/src/machine/instruction.cpp
+++ b/src/machine/instruction.cpp
@@ -1375,7 +1375,7 @@ bool parse_immediate_value(
 
 uint16_t parse_csr_address(const QString &field_token, uint &chars_taken) {
     if (field_token.at(0).isLetter()) {
-        size_t index = CSR::REGISTER_MAP_BY_NAME.at(qPrintable(field_token));
+        size_t index = CSR::REGISTER_MAP_BY_NAME.at(field_token.toStdString());
         if (index < 0) {
             chars_taken = 0;
             return 0;