diff --git a/code/M3D/M3DWrapper.h b/code/M3D/M3DWrapper.h
index ffd9e233e..f404d3d4b 100644
--- a/code/M3D/M3DWrapper.h
+++ b/code/M3D/M3DWrapper.h
@@ -50,6 +50,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include <memory>
 #include <vector>
+#include <string>
 
 #include "m3d.h"