1 files changed, 5 insertions, 0 deletions

diff --git a/src/solvers/coord/drfin.h b/src/solvers/coord/drfin.h
index 569419b..ec645a2 100644
--- a/src/solvers/coord/drfin.h
+++ b/src/solvers/coord/drfin.h
@@ -1,3 +1,6 @@
+#ifndef SOLVERS_COORD_DRFIN_H
+#define SOLVERS_COORD_DRFIN_H
+
 STATIC bool is_drfin_solvable(cube_t);
 
 STATIC multicoord_t multicoordinate_drfin = {
@@ -15,3 +18,5 @@ is_drfin_solvable(cube_t cube)
                coord_co(cube) == 0 &&
                issolvable((oriented_cube_t){.cube = cube, .orientation = 0});
 }
+
+#endif /* SOLVERS_COORD_DRFIN_H */