--- a/src/defaults.h.in
+++ b/src/defaults.h.in
@@ -116,32 +116,32 @@
 #define CANONICAL_HOST_TYPE %CANONICAL_HOST_TYPE%
 #endif
 
-extern string Voctave_home;
+extern std::string Voctave_home;
 
-extern string Vbin_dir;
-extern string Vinfo_dir;
-extern string Vdata_dir;
-extern string Vlibexec_dir;
-extern string Varch_lib_dir;
-extern string Vlocal_arch_lib_dir;
-extern string Vfcn_file_dir;
+extern std::string Vbin_dir;
+extern std::string Vinfo_dir;
+extern std::string Vdata_dir;
+extern std::string Vlibexec_dir;
+extern std::string Varch_lib_dir;
+extern std::string Vlocal_arch_lib_dir;
+extern std::string Vfcn_file_dir;
 
 // The path that will be searched for programs that we execute.
 // (--exec-path path)
-extern string Vexec_path;
+extern std::string Vexec_path;
 
 // And the cached directory path corresponding to Vload_path.
 extern dir_path Vload_path_dir_path;
 
 // Name of the editor to be invoked by the edit_history command.
-extern string Veditor;
+extern std::string Veditor;
 
-extern string Vimagepath;
+extern std::string Vimagepath;
 
-extern string Vlocal_site_defaults_file;
-extern string Vsite_defaults_file;
+extern std::string Vlocal_site_defaults_file;
+extern std::string Vsite_defaults_file;
 
-extern string maybe_add_default_load_path (const string& pathstring);
+extern std::string maybe_add_default_load_path (const std::string& pathstring);
 
 extern void install_defaults (void);