diff --git a/src/athena/DNAYaml.cpp b/src/athena/DNAYaml.cpp
index 43997ee..799fac6 100644
--- a/src/athena/DNAYaml.cpp
+++ b/src/athena/DNAYaml.cpp
@@ -1003,7 +1003,7 @@ bool YAMLDocWriter::RecursiveFinish(yaml_emitter_t* doc, const YAMLNode& node) {
   return true;
 }
 
-static const std::string base64_chars =
+constexpr std::string_view base64_chars =
     "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
     "abcdefghijklmnopqrstuvwxyz"
     "0123456789+/";