diff --git a/include/openmc/source.h b/include/openmc/source.h
index 16d91fc56..47761ff8c 100644
--- a/include/openmc/source.h
+++ b/include/openmc/source.h
@@ -68,7 +68,7 @@ Particle::Bank sample_external_source(uint64_t* seed);
 //! Sample a site from custom source library
 Particle::Bank sample_custom_source_library(uint64_t* seed);
 
-//Load custom source library
+//! Load custom source library
 void load_custom_source_library();
 
 //Release custom source library