diff --git a/include/spdlog/cfg/argv.h b/include/spdlog/cfg/argv.h
index 82bc1835..83e3546a 100644
--- a/include/spdlog/cfg/argv.h
+++ b/include/spdlog/cfg/argv.h
@@ -21,7 +21,7 @@ namespace spdlog {
 namespace cfg {
 
 // search for SPDLOG_LEVEL= in the args and use it to init the levels
-void load_argv_levels(int argc, const char **argv)
+inline void load_argv_levels(int argc, const char **argv)
 {
     const std::string spdlog_level_prefix = "SPDLOG_LEVEL=";
     for (int i = 1; i < argc; i++)
@@ -36,7 +36,7 @@ void load_argv_levels(int argc, const char **argv)
     }
 }
 
-void load_argv_levels(int argc, char **argv)
+inline void load_argv_levels(int argc, char **argv)
 {
     load_argv_levels(argc, const_cast<const char **>(argv));
 }