diff --git a/src/daycare.c b/src/daycare.c
index e29c0fc70..1c3f24ba3 100644
--- a/src/daycare.c
+++ b/src/daycare.c
@@ -32,7 +32,7 @@
 
 // Combination of RSE's Day-Care (re-used on Four Island), FRLG's Day-Care, and egg_hatch.c
 
-extern struct Evolution gEvolutionTable[][EVOS_PER_MON];
+extern const struct Evolution gEvolutionTable[][EVOS_PER_MON];
 
 struct EggHatchData
 {