diff --git a/stl/parser.h b/stl/parser.h
index 0989b3f..eccc7e3 100644
--- a/stl/parser.h
+++ b/stl/parser.h
@@ -18,6 +18,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #pragma once
 
 #include <math.h>
+#include <string>
 #include "triangle.h"
 #include "vec3.h"