diff --git a/src/p_polyobj.c b/src/p_polyobj.c
index f7545e5bd..bbcf4f42a 100644
--- a/src/p_polyobj.c
+++ b/src/p_polyobj.c
@@ -2873,54 +2873,29 @@ void T_PolyObjFade(polyfade_t *th)
 	if (po->thinker == NULL)
 		po->thinker = &th->thinker;
 
-	if (th->ticbased)
+	stillfading = th->ticbased ? !(--(th->timer) <= 0)
+		: !((th->timer -= th->duration) <= 0);
+
+	if (th->timer <= 0)
 	{
-		stillfading = !(--(th->timer) <= 0);
+		po->translucency = max(min(th->destvalue, NUMTRANSMAPS), 0);
 
-		if (th->timer <= 0)
-		{
-			po->translucency = max(min(th->destvalue, NUMTRANSMAPS), 0);
-
-			// remove thinker
-			if (po->thinker == &th->thinker)
-				po->thinker = NULL;
-			P_RemoveThinker(&th->thinker);
-		}
-		else
-		{
-			INT16 delta = abs(th->destvalue - th->sourcevalue);
-			fixed_t factor = min(FixedDiv(th->speed - th->timer, th->speed), 1*FRACUNIT);
-			if (th->destvalue < th->sourcevalue)
-				po->translucency = max(min(po->translucency, th->sourcevalue - (INT16)FixedMul(delta, factor)), th->destvalue);
-			else if (th->destvalue > th->sourcevalue)
-				po->translucency = min(max(po->translucency, th->sourcevalue + (INT16)FixedMul(delta, factor)), th->destvalue);
-		}
+		// remove thinker
+		if (po->thinker == &th->thinker)
+			po->thinker = NULL;
+		P_RemoveThinker(&th->thinker);
 	}
 	else
 	{
-		fixed_t timerdest = FixedMul(FixedDiv(256, NUMTRANSMAPS), NUMTRANSMAPS-th->destvalue);
-
-		if (th->destvalue > th->sourcevalue) // fading out, destvalue is higher
-		{
-			// for timer, lower is transparent, higher is opaque
-			stillfading = (th->timer > timerdest);
-			th->timer = max(timerdest, th->timer - th->speed);
-		}
-		else if (th->destvalue < th->sourcevalue) // fading in, destvalue is lower
-		{	stillfading = (th->timer < timerdest);
-			th->timer = min(timerdest, th->timer + th->speed);
-		}
-
-		if (!stillfading)
-		{
-			po->translucency = max(min(th->destvalue, NUMTRANSMAPS), 0);
-			// remove thinker
-			if (po->thinker == &th->thinker)
-				po->thinker = NULL;
-			P_RemoveThinker(&th->thinker);
-		}
-		else
-			po->translucency = FixedDiv(256-th->timer, FixedDiv(256, NUMTRANSMAPS));
+		INT16 delta = abs(th->destvalue - th->sourcevalue);
+		INT32 duration = th->ticbased ? th->duration
+			: abs(FixedMul(FixedDiv(256, NUMTRANSMAPS), NUMTRANSMAPS - th->destvalue)
+				- FixedMul(FixedDiv(256, NUMTRANSMAPS), NUMTRANSMAPS - th->sourcevalue)); // speed-based internal counter duration: delta in 256 scale
+		fixed_t factor = min(FixedDiv(duration - th->timer, duration), 1*FRACUNIT);
+		if (th->destvalue < th->sourcevalue)
+			po->translucency = max(min(po->translucency, th->sourcevalue - (INT16)FixedMul(delta, factor)), th->destvalue);
+		else if (th->destvalue > th->sourcevalue)
+			po->translucency = min(max(po->translucency, th->sourcevalue + (INT16)FixedMul(delta, factor)), th->destvalue);
 	}
 
 	if (!stillfading)
@@ -3010,13 +2985,14 @@ INT32 EV_DoPolyObjFade(polyfadedata_t *pfdata)
 	if (pfdata->ticbased)
 	{
 		th->ticbased = true;
-		th->timer = th->speed = abs(pfdata->speed); // use th->speed for total duration
+		th->timer = th->duration = abs(pfdata->speed); // pfdata->speed is duration
 	}
 	else
 	{
 		th->ticbased = false;
-		th->timer = FixedMul(FixedDiv(256, NUMTRANSMAPS), NUMTRANSMAPS - po->translucency); // use as internal counter
-		th->speed = pfdata->speed;
+		th->timer = abs(FixedMul(FixedDiv(256, NUMTRANSMAPS), NUMTRANSMAPS - th->destvalue)
+			- FixedMul(FixedDiv(256, NUMTRANSMAPS), NUMTRANSMAPS - th->sourcevalue)); // delta converted to 256 scale, use as internal counter
+		th->duration = abs(pfdata->speed); // use th->duration as speed decrement
 	}
 
 	oldpo = po;
diff --git a/src/p_polyobj.h b/src/p_polyobj.h
index 61404112c..524518f2a 100644
--- a/src/p_polyobj.h
+++ b/src/p_polyobj.h
@@ -217,8 +217,8 @@ typedef struct polyfade_s
 	boolean docollision;
 	boolean doghostfade;
 	boolean ticbased;
+	INT32 duration;
 	INT32 timer;
-	INT32 speed;
 } polyfade_t;
 
 //
diff --git a/src/p_saveg.c b/src/p_saveg.c
index 2bfc5859a..11c481be8 100644
--- a/src/p_saveg.c
+++ b/src/p_saveg.c
@@ -1710,8 +1710,8 @@ static void SavePolyfadeThinker(const thinker_t *th, const UINT8 type)
 	WRITEUINT8(save_p, (UINT8)ht->docollision);
 	WRITEUINT8(save_p, (UINT8)ht->doghostfade);
 	WRITEUINT8(save_p, (UINT8)ht->ticbased);
+	WRITEINT32(save_p, ht->duration);
 	WRITEINT32(save_p, ht->timer);
-	WRITEINT32(save_p, ht->speed);
 }
 
 #endif
@@ -2725,8 +2725,8 @@ static void LoadPolyfadeThinker(actionf_p1 thinker)
 	ht->docollision = (boolean)READUINT8(save_p);
 	ht->doghostfade = (boolean)READUINT8(save_p);
 	ht->ticbased = (boolean)READUINT8(save_p);
+	ht->duration = READINT32(save_p);
 	ht->timer = READINT32(save_p);
-	ht->speed = READINT32(save_p);
 	P_AddThinker(&ht->thinker);
 }
 #endif