diff --git a/source/core/gamecontrol.cpp b/source/core/gamecontrol.cpp
index 0f080054e..56e6220cb 100644
--- a/source/core/gamecontrol.cpp
+++ b/source/core/gamecontrol.cpp
@@ -1038,10 +1038,9 @@ void S_SetSoundPaused(int state)
 	}
 }
 
-int CalcSmoothRatio(ClockTicks totalclk, ClockTicks ototalclk, int realgameticspersec)
+double CalcSmoothRatio(ClockTicks totalclk, ClockTicks ototalclk, int realgameticspersec)
 {
-	double ratio;
-	int result;
+	double ratio, result;
 
 	if (cl_debugintrpl)
 	{
@@ -1075,11 +1074,11 @@ int CalcSmoothRatio(ClockTicks totalclk, ClockTicks ototalclk, int realgameticsp
 		ratio = (0.5 + (totalclk - ototalclk)) / (120 / realgameticspersec);
 	}
 
-	result = clamp(xs_CRoundToInt(ratio * MaxSmoothRatio), 0, MaxSmoothRatio);
+	result = fclamp2(ratio * MaxSmoothRatio, 0., MaxSmoothRatio);
 
 	if (cl_debugintrpl)
 	{
-		Printf("ratio: %f\nresult: %d\n", ratio, result);
+		Printf("ratio: %f\nresult: %f\n", ratio, result);
 	}
 
 	return result;
diff --git a/source/core/gamecontrol.h b/source/core/gamecontrol.h
index d4ead5fda..d39fee2e7 100644
--- a/source/core/gamecontrol.h
+++ b/source/core/gamecontrol.h
@@ -192,7 +192,7 @@ void S_ResumeSound(bool notsfx);
 void S_SetSoundPaused(int state);
 
 void G_FatalEngineError(void);
-int CalcSmoothRatio(ClockTicks totalclk, ClockTicks ototalclk, int realgameticspersec);
+double CalcSmoothRatio(ClockTicks totalclk, ClockTicks ototalclk, int realgameticspersec);
 enum
 {
 	MaxSmoothRatio = FRACUNIT
diff --git a/source/games/duke/src/funct.h b/source/games/duke/src/funct.h
index f9cb3511f..736406e40 100644
--- a/source/games/duke/src/funct.h
+++ b/source/games/duke/src/funct.h
@@ -211,7 +211,7 @@ void dobonus(int bonusonly, const CompletionFunc& completion);
 void dobonus_d(bool bonusonly, const CompletionFunc& completion);
 void dobonus_r(bool bonusonly, const CompletionFunc& completion);
 
-void displayrest(int32_t smoothratio);
+void displayrest(double smoothratio);
 void drawbackground(void);
 void displayrooms(int32_t playerNum, int32_t smoothratio);
 void setgamepalette(int palid);
diff --git a/source/games/duke/src/game_misc.cpp b/source/games/duke/src/game_misc.cpp
index 6466147d8..b6df76400 100644
--- a/source/games/duke/src/game_misc.cpp
+++ b/source/games/duke/src/game_misc.cpp
@@ -234,7 +234,7 @@ void V_AddBlend (float r, float g, float b, float a, float v_blend[4])
 //
 //---------------------------------------------------------------------------
 
-void displayrest(int smoothratio)
+void displayrest(double smoothratio)
 {
 	int i, j;
 	unsigned char fader = 0, fadeg = 0, fadeb = 0, fadef = 0, tintr = 0, tintg = 0, tintb = 0, tintf = 0, dotint = 0;
diff --git a/source/games/duke/src/gameloop.cpp b/source/games/duke/src/gameloop.cpp
index 859913feb..a9482c60d 100644
--- a/source/games/duke/src/gameloop.cpp
+++ b/source/games/duke/src/gameloop.cpp
@@ -342,7 +342,7 @@ bool GameTicker()
 	{
 		ototalclock = totalclock - 1;
 	}
-	int const smoothRatio = calc_smoothratio(totalclock, ototalclock);
+	double const smoothRatio = calc_smoothratio(totalclock, ototalclock);
 
 	gameupdatetime.Unclock();