diff --git a/test/battle/trainer_control.c b/test/battle/trainer_control.c
index 99bea0e8cc..810a721fa5 100644
--- a/test/battle/trainer_control.c
+++ b/test/battle/trainer_control.c
@@ -123,7 +123,7 @@ TEST("CreateNPCTrainerPartyForTrainer generates different personalities for diff
 
 TEST("ModifyPersonalityForNature can set any nature")
 {
-    u32 personality, nature, j, k;
+    u32 personality = 0, nature = 0, j = 0, k = 0;
     for (j = 0; j < 64; j++)
     {
         for (k = 0; k < NUM_NATURES; k++)