diff --git a/BaseLib/StringTools.h b/BaseLib/StringTools.h
index 6b4bbca2cd38cc519644f970c9897bef010e6817..0032857a4b893051c47155503e92ced15ac6e9f1 100644
--- a/BaseLib/StringTools.h
+++ b/BaseLib/StringTools.h
@@ -71,7 +71,7 @@ template<typename T> T str2number (const std::string &str)
 void trim(std::string &str, char ch=' ');
 
 /**
- * Returs same string with all characters in upper case.
+ * Returns same string with all characters in upper case.
  *
  * This uses std::toupper() function, and does not care about unicode.
  */