diff --git a/data/battle_scripts_1.s b/data/battle_scripts_1.s
index 51090237bc..5d2e18cb4b 100644
--- a/data/battle_scripts_1.s
+++ b/data/battle_scripts_1.s
@@ -1452,6 +1452,7 @@ BattleScript_StrengthSapHp:
 	jumpifstatus3 BS_ATTACKER, STATUS3_HEAL_BLOCK, BattleScript_MoveEnd
 	jumpiffullhp BS_ATTACKER, BattleScript_MoveEnd
 	manipulatedamage DMG_BIG_ROOT
+	orword gHitMarker, HITMARKER_IGNORE_SUBSTITUTE
 	healthbarupdate BS_ATTACKER
 	datahpupdate BS_ATTACKER
 	printstring STRINGID_PKMNENERGYDRAINED
diff --git a/test/battle/move_effect/strength_sap.c b/test/battle/move_effect/strength_sap.c
new file mode 100644
index 0000000000..c549e4c332
--- /dev/null
+++ b/test/battle/move_effect/strength_sap.c
@@ -0,0 +1,59 @@
+#include "global.h"
+#include "test/battle.h"
+
+ASSUMPTIONS
+{
+    ASSUME(gBattleMoves[MOVE_STRENGTH_SAP].effect == EFFECT_STRENGTH_SAP);
+}
+
+SINGLE_BATTLE_TEST("Strength Sap lowers Attack by 1 and restores HP based on target's Attack Stat", s16 hp)
+{
+    u32 atkStat = 0;
+
+    PARAMETRIZE{ atkStat = 100; }
+    PARAMETRIZE{ atkStat = 50; }
+
+    GIVEN {
+        PLAYER(SPECIES_WOBBUFFET) { HP(200); }
+        OPPONENT(SPECIES_WOBBUFFET) { Attack(atkStat); }
+    } WHEN {
+        TURN { MOVE(player, MOVE_STRENGTH_SAP); }
+    } SCENE {
+        MESSAGE("Wobbuffet used Strength Sap!");
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_STRENGTH_SAP, player);
+        ANIMATION(ANIM_TYPE_GENERAL, B_ANIM_STATS_CHANGE, opponent);
+        MESSAGE("Foe Wobbuffet's Attack fell!");
+        HP_BAR(player, captureDamage: &results[i].hp);
+        MESSAGE("Foe Wobbuffet had its energy drained!");
+    } THEN {
+        EXPECT_EQ(results[i].hp * -1, atkStat);
+    }
+}
+
+// Same as above, but Substitute is used before Strength Sap.
+SINGLE_BATTLE_TEST("Strength Sap works exactly the same when attacker is behind substitute", s16 hp)
+{
+    u32 atkStat = 0;
+
+    PARAMETRIZE{ atkStat = 100; }
+    PARAMETRIZE{ atkStat = 50; }
+
+    GIVEN {
+        PLAYER(SPECIES_WOBBUFFET) { HP(200); }
+        OPPONENT(SPECIES_WOBBUFFET) { Attack(atkStat); }
+    } WHEN {
+        TURN { MOVE(player, MOVE_SUBSTITUTE); }
+        TURN { MOVE(player, MOVE_STRENGTH_SAP); }
+    } SCENE {
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_SUBSTITUTE, player);
+        MESSAGE("Wobbuffet used Strength Sap!");
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_STRENGTH_SAP, player);
+        ANIMATION(ANIM_TYPE_GENERAL, B_ANIM_STATS_CHANGE, opponent);
+        MESSAGE("Foe Wobbuffet's Attack fell!");
+        HP_BAR(player, captureDamage: &results[i].hp);
+        NOT MESSAGE("The SUBSTITUTE took damage for Foe Wobbuffet!");
+        MESSAGE("Foe Wobbuffet had its energy drained!");
+    } THEN {
+        EXPECT_EQ(results[i].hp * -1, atkStat);
+    }
+}