diff --git a/Contractor/GeometryCompressor.h b/Contractor/GeometryCompressor.h
index 439904a38..7c4fba45c 100644
--- a/Contractor/GeometryCompressor.h
+++ b/Contractor/GeometryCompressor.h
@@ -29,6 +29,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include <unordered_map>
 
+#include <string>
 #include <vector>
 
 #ifndef GEOMETRY_COMPRESSOR_H