diff --git a/neo/renderer/qgl_proc.h b/neo/renderer/qgl_proc.h
index 54ef43d9..af0146d0 100644
--- a/neo/renderer/qgl_proc.h
+++ b/neo/renderer/qgl_proc.h
@@ -38,6 +38,7 @@ QGLPROC(glBegin, void, (GLenum mode))
 QGLPROC(glBindTexture, void, (GLenum target, GLuint texture))
 QGLPROC(glBitmap, void, (GLsizei width, GLsizei height, GLfloat xorig, GLfloat yorig, GLfloat xmove, GLfloat ymove, const GLubyte *bitmap))
 QGLPROC(glBlendFunc, void, (GLenum sfactor, GLenum dfactor))
+QGLPROC(glBlendEquation, void, (GLenum mode))
 QGLPROC(glCallList, void, (GLuint list))
 QGLPROC(glCallLists, void, (GLsizei n, GLenum type, const GLvoid *lists))
 QGLPROC(glClear, void, (GLbitfield mask))
diff --git a/neo/renderer/tr_backend.cpp b/neo/renderer/tr_backend.cpp
index 18224a00..77ee7d8e 100644
--- a/neo/renderer/tr_backend.cpp
+++ b/neo/renderer/tr_backend.cpp
@@ -529,6 +529,31 @@ const void	RB_SwapBuffers( const void *data ) {
 		RB_ShowImages();
 	}
 
+#if 01 // set alpha chan to 1.0:
+	bool blendEnabled = qglIsEnabled( GL_BLEND );
+	//if ( !blendEnabled )
+		qglEnable( GL_BLEND );
+	qglBlendEquation( GL_FUNC_ADD );
+	qglBlendFunc( GL_ONE, GL_ONE );
+
+	// draw screen-sized quad with color (0.0, 0.0, 0.0, 1.0)
+	int w = glConfig.vidWidth, h = glConfig.vidHeight;
+	int x = 0, y = 0;
+	qglColor4f( 0.5f, 0.0f, 0.0f, 1.0f );
+	qglBegin( GL_QUADS );
+		qglVertex2f( x, y );
+		qglVertex2f( x + w, y );
+		qglVertex2f( x + w, y + h );
+		qglVertex2f( x, y + h );
+	qglEnd();
+
+	// restore default or previous states
+	qglBlendEquation( GL_FUNC_ADD );
+	if ( !blendEnabled )
+		qglDisable( GL_BLEND );
+	// TODO: theoretically I should restore the glColor value, but I'm sure it'll be set before it's needed anyway
+#endif
+
 	// force a gl sync if requested
 	if ( r_finish.GetBool() ) {
 		qglFinish();
diff --git a/neo/sys/stub/stub_gl.cpp b/neo/sys/stub/stub_gl.cpp
index 1296aeb0..af571081 100644
--- a/neo/sys/stub/stub_gl.cpp
+++ b/neo/sys/stub/stub_gl.cpp
@@ -44,6 +44,7 @@ void APIENTRY glBegin(GLenum mode){};
 void APIENTRY glBindTexture(GLenum target, GLuint texture){};
 void APIENTRY glBitmap(GLsizei width, GLsizei height, GLfloat xorig, GLfloat yorig, GLfloat xmove, GLfloat ymove, const GLubyte *bitmap){};
 void APIENTRY glBlendFunc(GLenum sfactor, GLenum dfactor){};
+void APIENTRY glBlendEquation(GLenum mode){};
 void APIENTRY glCallList(GLuint list){};
 void APIENTRY glCallLists(GLsizei n, GLenum type, const GLvoid *lists){};
 void APIENTRY glClear(GLbitfield mask){};