diff --git a/asm/include/overlay_29_02314810.inc b/asm/include/overlay_29_02314810.inc
index 232ac858..fe80195c 100644
--- a/asm/include/overlay_29_02314810.inc
+++ b/asm/include/overlay_29_02314810.inc
@@ -12,9 +12,10 @@
 .public GetExclusiveItemWithEffectFromBag
 .public IsProtectedFromNegativeStatus
 .public ItemIsActive__0231513C
+.public LowerSpeed
 .public LogMessageByIdWithPopupCheckUserTarget
 .public ov10_022C4618
-.public ov10_022C488C
+.public gSpeedLowerTurnRange
 .public ov10_022C4890
 .public ov29_022E41CC
 .public ov29_022E44CC
diff --git a/asm/overlay_10_rodata_022C464C.s b/asm/overlay_10_rodata_022C464C.s
index 0086b7df..cff47569 100644
--- a/asm/overlay_10_rodata_022C464C.s
+++ b/asm/overlay_10_rodata_022C464C.s
@@ -434,8 +434,8 @@ gCringeTurnRange:
 	.global SPEED_BOOST_TURN_RANGE
 SPEED_BOOST_TURN_RANGE:
 	.byte 0x08, 0x00, 0x0A, 0x00
-	.global ov10_022C488C
-ov10_022C488C:
+	.global gSpeedLowerTurnRange
+gSpeedLowerTurnRange:
 	.byte 0x06, 0x00, 0x08, 0x00
 	.global ov10_022C4890
 ov10_022C4890:
diff --git a/asm/overlay_29_02314810.s b/asm/overlay_29_02314810.s
index a18d11c6..6bdfbf5b 100644
--- a/asm/overlay_29_02314810.s
+++ b/asm/overlay_29_02314810.s
@@ -4,134 +4,6 @@
 	.text
 
 
-	arm_func_start BoostSpeedOneStage
-BoostSpeedOneStage: ; 0x0231493C
-	stmdb sp!, {r3, lr}
-	str r3, [sp]
-	mov r3, r2
-	mov r2, #1
-	bl BoostSpeed
-	ldmia sp!, {r3, pc}
-	arm_func_end BoostSpeedOneStage
-
-	arm_func_start LowerSpeed
-LowerSpeed: ; 0x02314954
-	stmdb sp!, {r3, r4, r5, r6, r7, r8, sb, sl, fp, lr}
-	mov sb, r1
-	mov sl, r0
-	mov r0, sb
-	mov r8, r2
-	mov r7, r3
-	bl EntityIsValid__023118B4
-	cmp r0, #0
-	ldmeqia sp!, {r3, r4, r5, r6, r7, r8, sb, sl, fp, pc}
-	mov r0, sl
-	mov r1, sb
-	mov r2, r7
-	bl SafeguardIsActive
-	cmp r0, #0
-	ldmneia sp!, {r3, r4, r5, r6, r7, r8, sb, sl, fp, pc}
-	mov r0, sl
-	mov r1, sb
-	mov r2, r7
-	bl IsProtectedFromNegativeStatus
-	cmp r0, #0
-	ldmneia sp!, {r3, r4, r5, r6, r7, r8, sb, sl, fp, pc}
-	mov r0, #0
-	mov r1, sb
-	mov r2, r0
-	ldr r4, [sb, #0xb4]
-	bl SubstitutePlaceholderStringTags
-	mov r0, sb
-	bl CalcSpeedStageWrapper
-	movs fp, r0
-	bne _023149E8
-	cmp r7, #0
-	beq _02314AA0
-	ldr r2, _02314AAC ; =0x00000DDC
-	mov r0, sl
-	mov r1, sb
-	bl LogMessageByIdWithPopupCheckUserTarget
-	b _02314AA0
-_023149E8:
-	mov r5, #0
-	b _02314A34
-_023149F0:
-	mov r1, #0
-	b _02314A28
-_023149F8:
-	add r6, r4, r1
-#ifdef JAPAN
-	ldrb r0, [r6, #0x115]
-#else
-	ldrb r0, [r6, #0x119]
-#endif
-	cmp r0, #0
-	bne _02314A24
-	ldr r1, _02314AB0 ; =ov10_022C488C
-	mov r0, sb
-	mov r2, #1
-	bl CalcStatusDuration
-	add r0, r0, #1
-#ifdef JAPAN
-	strb r0, [r6, #0x115]
-#else
-	strb r0, [r6, #0x119]
-#endif
-	b _02314A30
-_02314A24:
-	add r1, r1, #1
-_02314A28:
-	cmp r1, #5
-	blt _023149F8
-_02314A30:
-	add r5, r5, #1
-_02314A34:
-	cmp r5, r8
-	blt _023149F0
-	mov r0, sb
-	bl CalcSpeedStageWrapper
-	mov r4, r0
-	cmp fp, r4
-	bne _02314A6C
-	cmp r7, #0
-	beq _02314AA0
-	ldr r2, _02314AB4 ; =0x00000DDA
-	mov r0, sl
-	mov r1, sb
-	bl LogMessageByIdWithPopupCheckUserTarget
-	b _02314AA0
-_02314A6C:
-	mov r0, sb
-	bl ov29_022E451C
-	ldr r0, _02314AB8 ; =ov29_02353318
-	mov r1, r4, lsl #1
-	ldrh r2, [r0, r1]
-	mov r0, sl
-	mov r1, sb
-	bl LogMessageByIdWithPopupCheckUserTarget
-	cmp r4, #0
-	bne _02314AA0
-	mov r0, sl
-	mov r1, sb
-	bl TryActivateQuickFeet
-_02314AA0:
-	mov r0, sb
-	bl UpdateStatusIconFlags
-	ldmia sp!, {r3, r4, r5, r6, r7, r8, sb, sl, fp, pc}
-	.align 2, 0
-#ifdef JAPAN
-_02314AAC: .word 0x00000B1C
-_02314AB0: .word ov10_022C488C
-_02314AB4: .word 0x00000B1A
-#else
-_02314AAC: .word 0x00000DDC
-_02314AB0: .word ov10_022C488C
-_02314AB4: .word 0x00000DDA
-#endif
-_02314AB8: .word ov29_02353318
-	arm_func_end LowerSpeed
-
 	arm_func_start TrySealMove
 TrySealMove: ; 0x02314ABC
 	stmdb sp!, {r4, r5, r6, r7, r8, sb, lr}
diff --git a/include/overlay_29_02313814.h b/include/overlay_29_02313814.h
index 9e1fa15e..309bd901 100644
--- a/include/overlay_29_02313814.h
+++ b/include/overlay_29_02313814.h
@@ -37,5 +37,7 @@ bool8 TryInflictParalysisStatus(struct entity *user, struct entity *target, bool
 // Checks if a monster is a team member under the effects of a certain exclusive item effect.
 bool8 ExclusiveItemEffectIsActive__023147EC(struct entity *entity, enum exclusive_item_effect_id effect_id);
 void BoostSpeed(struct entity *user, struct entity *target, s32 nStages, s32 turns, bool8 displayMessage);
+void BoostSpeedOneStage(struct entity *user, struct entity *target, s32 turns, bool8 displayMessage);
+void LowerSpeed(struct entity *user, struct entity *target, s32 nStages, bool8 displayMessage);
 
 #endif //PMDSKY_OVERLAY_29_02313814_H
diff --git a/src/overlay_29_02313814.c b/src/overlay_29_02313814.c
index 05bd87d4..d371c8ec 100644
--- a/src/overlay_29_02313814.c
+++ b/src/overlay_29_02313814.c
@@ -29,6 +29,7 @@ extern void ov29_022E4338(struct entity *);
 extern void PlayCringeExclamationPointEffect(struct entity *);
 extern void ov29_022E4240(struct entity *);
 extern void ov29_022E44CC(struct entity *);
+extern void ov29_022E451C(struct entity *);
 extern fx32_8 MultiplyByFixedPoint(fx32_8 a, fx32_8 b);
 extern bool8 IsProtectedFromNegativeStatus(struct entity *user ,struct entity *target, bool8 displayMessage);
 extern bool8 SafeguardIsActive(struct entity *user ,struct entity *target, bool8 displayMessage);
@@ -45,6 +46,7 @@ extern int CalcSpeedStage(struct entity *, int);
 
 extern const s16 gCringeTurnRange[];
 extern const s16 gParalysisTurnRange[];
+extern const s16 gSpeedLowerTurnRange[];
 extern const s16 SPEED_BOOST_TURN_RANGE[];
 extern const u16 ov29_02353318[];
 
@@ -736,3 +738,57 @@ void BoostSpeed(struct entity *user, struct entity *target, s32 nStages, s32 tur
 
     UpdateStatusIconFlags(target);
 }
+
+void BoostSpeedOneStage(struct entity *user, struct entity *target, s32 turns, bool8 displayMessage)
+{
+    BoostSpeed(user, target, 1, turns, displayMessage);
+}
+
+void LowerSpeed(struct entity *user, struct entity *target, s32 nStages, bool8 displayMessage)
+{
+    s32 speedBefore;
+    s32 speedAfter;
+    struct monster *entityInfo;
+
+    if (!EntityIsValid__023118B4(target))
+        return;
+
+    if (SafeguardIsActive(user,target,displayMessage))
+        return;
+
+    if (IsProtectedFromNegativeStatus(user, target, displayMessage))
+        return;
+
+    entityInfo = GetEntInfo(target);
+    SubstitutePlaceholderStringTags(0,target,0);
+    speedBefore = CalcSpeedStageWrapper(target);
+    if (speedBefore == 0) {
+        if (displayMessage)
+            LogMessageByIdWithPopupCheckUserTarget(user,target,0xddc + JPN_MSG_OFFSET);
+    }
+    else {
+        s32 counter, i;
+        for (counter = 0; counter < nStages; counter++) {
+            for (i = 0; i < NUM_SPEED_COUNTERS; i++) {
+                if (entityInfo->speed_down_counters[i] == 0) {
+                    entityInfo->speed_down_counters[i] = CalcStatusDuration(target,gSpeedLowerTurnRange,TRUE) + 1;
+                    break;
+                }
+            }
+        }
+        speedAfter = CalcSpeedStageWrapper(target);
+        if (speedBefore == speedAfter) {
+            if (displayMessage)
+                LogMessageByIdWithPopupCheckUserTarget(user,target,0xdda + JPN_MSG_OFFSET);
+        }
+        else {
+            ov29_022E451C(target);
+            LogMessageByIdWithPopupCheckUserTarget(user,target,ov29_02353318[speedAfter]);
+            if (speedAfter == 0) {
+                TryActivateQuickFeet(user, target);
+            }
+        }
+    }
+
+    UpdateStatusIconFlags(target);
+}