diff --git a/src/SDLx/Controller/Interface.xs b/src/SDLx/Controller/Interface.xs
index 3dc202b7..d326c885 100644
--- a/src/SDLx/Controller/Interface.xs
+++ b/src/SDLx/Controller/Interface.xs
@@ -57,15 +57,15 @@ void evaluate(SDLx_Interface *obj, SDLx_Derivative *out, SDLx_State *initial, fl
 
 	SV *temp;
 	temp           = av_pop(accel);
-	out->dv_x      = sv_nv(temp);
+	out->dv_x      = SvNVx(temp);
 	SvREFCNT_dec(temp);
 
 	temp           = av_pop(accel);
-	out->dv_y      = sv_nv(temp);
+	out->dv_y      = SvNVx(temp);
 	SvREFCNT_dec(temp);
 
 	temp           = av_pop(accel);
-	out->dang_v    = sv_nv(temp);
+	out->dang_v    = SvNVx(temp);
 	SvREFCNT_dec(temp);
 
 	SvREFCNT_dec((SV *)accel);
@@ -90,15 +90,15 @@ void evaluate_dt(SDLx_Interface *obj, SDLx_Derivative *out, SDLx_State *initial,
 
 	SV *temp;
 	temp           = av_pop(accel);
-	out->dv_x      = sv_nv(temp);
+	out->dv_x      = SvNVx(temp);
 	SvREFCNT_dec(temp);
 
 	temp           = av_pop(accel);
-	out->dv_y      = sv_nv(temp);
+	out->dv_y      = SvNVx(temp);
 	SvREFCNT_dec(temp);
 
 	temp           = av_pop(accel);
-	out->dang_v    = sv_nv(temp);
+	out->dang_v    = SvNVx(temp);
 	SvREFCNT_dec(temp);
 
 	SvREFCNT_dec((SV *)accel);