diff --git a/src/hardware/hw_defs.h b/src/hardware/hw_defs.h
index 9cb48620e..3752cbf05 100644
--- a/src/hardware/hw_defs.h
+++ b/src/hardware/hw_defs.h
@@ -219,7 +219,8 @@ enum EPolyFlags
 	PF_Substractive     = 0x00000010,   // for splat
 	PF_NoAlphaTest      = 0x00000020,   // hiden param
 	PF_Fog              = 0x00000040,   // Fog blocks
-	PF_Blending         = (PF_Environment|PF_Additive|PF_Translucent|PF_Masked|PF_Substractive|PF_Fog)&~PF_NoAlphaTest,
+	PF_Invert           = 0x00000080,   // Polygon inverts the colours of what it's in front of
+	PF_Blending         = (PF_Environment|PF_Additive|PF_Translucent|PF_Masked|PF_Substractive|PF_Fog|PF_Invert)&~PF_NoAlphaTest,
 
 	// other flag bits
 
diff --git a/src/hardware/hw_draw.c b/src/hardware/hw_draw.c
index 69f37a29b..d3812983e 100644
--- a/src/hardware/hw_draw.c
+++ b/src/hardware/hw_draw.c
@@ -697,6 +697,27 @@ void HWR_DrawConsoleBack(UINT32 color, INT32 height)
 	HWD.pfnDrawPolygon(&Surf, v, 4, PF_NoTexture|PF_Modulated|PF_Translucent|PF_NoDepthTest);
 }
 
+void HWR_EncoreInvertScreen(void)
+{
+	FOutVector v[4];
+	FSurfaceInfo Surf;
+
+	v[0].x = v[3].x = -1.0f;
+	v[2].x = v[1].x =  1.0f;
+	v[0].y = v[1].y = -1.0f;
+	v[2].y = v[3].y =  1.0f;
+	v[0].z = v[1].z = v[2].z = v[3].z = 1.0f;
+
+	v[0].s = v[3].s = 0.0f;
+	v[2].s = v[1].s = 1.0f;
+	v[0].t = v[1].t = 1.0f;
+	v[2].t = v[3].t = 0.0f;
+
+	Surf.PolyColor.rgba = 0xFFFFFFFF;
+
+	HWD.pfnDrawPolygon(&Surf, v, 4, PF_NoTexture|PF_Invert|PF_NoDepthTest);
+}
+
 // Very similar to HWR_DrawConsoleBack, except we draw from the middle(-ish) of the screen to the bottom.
 void HWR_DrawTutorialBack(UINT32 color, INT32 boxheight)
 {
diff --git a/src/hardware/hw_main.h b/src/hardware/hw_main.h
index 3efeca45b..dfefc2a2f 100644
--- a/src/hardware/hw_main.h
+++ b/src/hardware/hw_main.h
@@ -28,6 +28,7 @@ void HWR_Shutdown(void);
 void HWR_drawAMline(const fline_t *fl, INT32 color);
 void HWR_FadeScreenMenuBack(UINT16 color, UINT8 strength);
 void HWR_DrawConsoleBack(UINT32 color, INT32 height);
+void HWR_EncoreInvertScreen(void);
 void HWR_DrawTutorialBack(UINT32 color, INT32 boxheight);
 void HWR_RenderSkyboxView(player_t *player);
 void HWR_RenderPlayerView(void);
diff --git a/src/hardware/r_opengl/r_opengl.c b/src/hardware/r_opengl/r_opengl.c
index 9e9bbee81..ceea6558d 100644
--- a/src/hardware/r_opengl/r_opengl.c
+++ b/src/hardware/r_opengl/r_opengl.c
@@ -1599,6 +1599,10 @@ EXPORT void HWRAPI(SetBlend) (FBITFIELD PolyFlags)
 					pglBlendFunc(GL_SRC_ALPHA, GL_SRC_COLOR);
 					pglAlphaFunc(GL_ALWAYS, 0.0f); // Don't discard zero alpha fragments
 					break;
+				case PF_Invert & PF_Invert:
+					pglBlendFunc(GL_ONE_MINUS_DST_COLOR, GL_ZERO);
+					pglAlphaFunc(GL_GREATER, 0.5f);
+					break;
 				default : // must be 0, otherwise it's an error
 					// No blending
 					pglBlendFunc(GL_ONE, GL_ZERO);   // the same as no blending
diff --git a/src/v_video.c b/src/v_video.c
index 6ccddd89d..31c7eec95 100644
--- a/src/v_video.c
+++ b/src/v_video.c
@@ -1505,7 +1505,7 @@ void V_EncoreInvertScreen(void)
 #ifdef HWRENDER
 	if (rendermode != render_soft && rendermode != render_none)
 	{
-		//HWR_EncoreInvertScreen();
+		HWR_EncoreInvertScreen();
 		return;
 	}
 #endif