diff --git a/toolsrc/include/vcpkg_Enums.h b/toolsrc/include/vcpkg_Enums.h
index 08fdc64bc6..c75feaa1f4 100644
--- a/toolsrc/include/vcpkg_Enums.h
+++ b/toolsrc/include/vcpkg_Enums.h
@@ -4,7 +4,7 @@
 
 namespace vcpkg::Enums
 {
-    std::string nullvalue_to_string(const std::string& enum_name);
+    std::string nullvalue_to_string(const CStringView enum_name);
 
-    [[noreturn]] void nullvalue_used(const LineInfo& line_info, const std::string& enum_name);
+    [[noreturn]] void nullvalue_used(const LineInfo& line_info, const CStringView enum_name);
 }
diff --git a/toolsrc/src/vcpkg_Enums.cpp b/toolsrc/src/vcpkg_Enums.cpp
index 41479d5923..51ba9d5dcd 100644
--- a/toolsrc/src/vcpkg_Enums.cpp
+++ b/toolsrc/src/vcpkg_Enums.cpp
@@ -5,9 +5,9 @@
 
 namespace vcpkg::Enums
 {
-    std::string nullvalue_to_string(const std::string& enum_name) { return Strings::format("%s_NULLVALUE", enum_name); }
+    std::string nullvalue_to_string(const CStringView enum_name) { return Strings::format("%s_NULLVALUE", enum_name); }
 
-    [[noreturn]] void nullvalue_used(const LineInfo& line_info, const std::string& enum_name)
+    [[noreturn]] void nullvalue_used(const LineInfo& line_info, const CStringView enum_name)
     {
         Checks::exit_with_message(line_info, "NULLVALUE of enum %s was used", enum_name);
     }