diff --git a/src/inspector_agent.cc b/src/inspector_agent.cc
index 1cbaa92b9abcea..9bbbeeac1bffd6 100644
--- a/src/inspector_agent.cc
+++ b/src/inspector_agent.cc
@@ -172,7 +172,7 @@ std::string GenerateID() {
 }
 
 // std::to_string is not available on Smart OS and ARM flavours
-const std::string to_string(uint64_t number) {
+inline const std::string to_string(uint64_t number) {
   std::ostringstream result;
   result << number;
   return result.str();