diff --git a/src/osd/modules/render/d3d/d3dhlsl.cpp b/src/osd/modules/render/d3d/d3dhlsl.cpp
index 5e390868f19..a6cfad8cae9 100644
--- a/src/osd/modules/render/d3d/d3dhlsl.cpp
+++ b/src/osd/modules/render/d3d/d3dhlsl.cpp
@@ -164,15 +164,15 @@ private:
 
 shaders::shaders() :
 	d3dintf(nullptr), machine(nullptr), d3d(nullptr), post_fx_enable(false), oversampling_enable(false),
-	update_t(true), num_screens(0), curr_screen(0), acc_t(0), delta_t(0), shadow_texture(nullptr),
-	options(nullptr), black_surface(nullptr), black_texture(nullptr), recording_movie(false),
-	render_snap(false), snap_copy_target(nullptr), snap_copy_texture(nullptr), snap_target(nullptr),
-	snap_texture(nullptr), snap_width(0), snap_height(0), initialized(false), backbuffer(nullptr),
-	curr_effect(nullptr), default_effect(nullptr), prescale_effect(nullptr), post_effect(nullptr),
-	distortion_effect(nullptr), focus_effect(nullptr), phosphor_effect(nullptr),
-	deconverge_effect(nullptr), color_effect(nullptr), ntsc_effect(nullptr), bloom_effect(nullptr),
-	downsample_effect(nullptr), vector_effect(nullptr), curr_texture(nullptr),
-	curr_render_target(nullptr), curr_poly(nullptr), d3dx_create_effect_from_file_ptr(nullptr)
+	num_screens(0), curr_screen(0), acc_t(0), delta_t(0), shadow_texture(nullptr), options(nullptr),
+	black_surface(nullptr), black_texture(nullptr), recording_movie(false), render_snap(false),
+	snap_copy_target(nullptr), snap_copy_texture(nullptr), snap_target(nullptr), snap_texture(nullptr),
+	snap_width(0), snap_height(0), initialized(false), backbuffer(nullptr), curr_effect(nullptr),
+	default_effect(nullptr), prescale_effect(nullptr), post_effect(nullptr), distortion_effect(nullptr),
+	focus_effect(nullptr), phosphor_effect(nullptr), deconverge_effect(nullptr), color_effect(nullptr),
+	ntsc_effect(nullptr), bloom_effect(nullptr), downsample_effect(nullptr), vector_effect(nullptr),
+	curr_texture(nullptr), curr_render_target(nullptr), curr_poly(nullptr),
+	d3dx_create_effect_from_file_ptr(nullptr)
 {
 }
 
@@ -820,6 +820,8 @@ int shaders::create_resources()
 
 void shaders::begin_draw()
 {
+	double t;
+
 	if (!enabled())
 	{
 		return;
@@ -827,6 +829,10 @@ void shaders::begin_draw()
 
 	curr_screen = 0;
 	curr_effect = default_effect;
+	// Update for delta_time
+	t = machine->time().as_double();
+	delta_t = t - acc_t;
+	acc_t = t;
 
 	default_effect->set_technique("ScreenTechnique");
 	post_effect->set_technique("DefaultTechnique");
@@ -901,20 +907,6 @@ void shaders::blit(
 	curr_effect->end();
 }
 
-double shaders::delta_time()
-{
-	double t;
-
-	if (update_t) {
-		t = machine->time().as_double();
-		delta_t = t - acc_t;
-		acc_t = t;
-		update_t = false;
-	}
-	return delta_t;
-}
-
-
 //============================================================
 //  shaders::find_render_target
 //============================================================
@@ -1429,8 +1421,6 @@ void shaders::render_quad(poly_info *poly, int vertnum)
 	else if (PRIMFLAG_GET_VECTORBUF(poly->flags()))
 	{
 		curr_screen = curr_screen < num_screens ? curr_screen : 0;
-		if (curr_screen == 0)
-			update_t = true;
 
 		int source_width = int(poly->prim_width() + 0.5f);
 		int source_height = int(poly->prim_height() + 0.5f);
diff --git a/src/osd/modules/render/d3d/d3dhlsl.h b/src/osd/modules/render/d3d/d3dhlsl.h
index 914cf4eaeae..ed25d2c52e8 100644
--- a/src/osd/modules/render/d3d/d3dhlsl.h
+++ b/src/osd/modules/render/d3d/d3dhlsl.h
@@ -320,7 +320,7 @@ private:
 
 	void                    render_snapshot(IDirect3DSurface9 *surface);
 	// Time since last call, only updates once per render of all screens
-	double                  delta_time();
+	double                  delta_time() { return delta_t; }
 	d3d_render_target*      find_render_target(int source_width, int source_height, uint32_t screen_index);
 
 	rgb_t                   apply_color_convolution(rgb_t color);
@@ -348,7 +348,6 @@ private:
 
 	bool                    post_fx_enable;             // overall enable flag
 	bool                    oversampling_enable;        // oversampling enable flag
-	bool                    update_t;                   // signal for delta_t to be updated
 	int                     num_screens;                // number of emulated physical screens
 	int                     curr_screen;                // current screen for render target operations
 	double                  acc_t;                      // accumulated machine time