1 files changed, 5 insertions, 0 deletions

diff --git a/src/solvers/h48/coordinate.h b/src/solvers/h48/coordinate.h
index 695efc3..acbb9c0 100644
--- a/src/solvers/h48/coordinate.h
+++ b/src/solvers/h48/coordinate.h
@@ -1,3 +1,6 @@
+#ifndef SOLVERS_H48_COORDINATE_H
+#define SOLVERS_H48_COORDINATE_H
+
 STATIC_INLINE uint64_t coord_h48(
     cube_t, const uint32_t [SIZE(COCSEP_TABLESIZE)], uint8_t);
 STATIC_INLINE uint64_t coord_h48_edges(cube_t, uint64_t, uint8_t, uint8_t);
@@ -68,3 +71,5 @@ invcoord_h48(
 
         return ret;
 }
+
+#endif /* SOLVERS_H48_COORDINATE_H */