diff --git a/source/blender/gpu/intern/gpu_compositing.c b/source/blender/gpu/intern/gpu_compositing.c
index b423c14bd4b..cf288070126 100644
--- a/source/blender/gpu/intern/gpu_compositing.c
+++ b/source/blender/gpu/intern/gpu_compositing.c
@@ -257,7 +257,7 @@ bool GPU_fx_compositor_initialize_passes(
         GPUFX *fx, const rcti *rect, const rcti *scissor_rect,
         const GPUFXSettings *fx_settings)
 {
-	int w = BLI_rcti_size_x(rect) + 1, h = BLI_rcti_size_y(rect) + 1;
+	int w = BLI_rcti_size_x(rect), h = BLI_rcti_size_y(rect);
 	char err_out[256];
 	int num_passes = 0;
 	char fx_flag = fx_settings->fx_flag;
@@ -282,6 +282,12 @@ bool GPU_fx_compositor_initialize_passes(
 		return false;
 	}
 
+	/* scissor is missing when drawing offscreen, in that case, dimensions match exactly. In opposite case
+	 * add one to match viewport dimensions */
+	if (!scissor_rect) {
+		w++, h++;
+	}
+
 	fx->num_passes = 0;
 	/* dof really needs a ping-pong buffer to work */
 	if (fx_flag & GPU_FX_FLAG_DOF)
diff --git a/source/blender/gpu/shaders/gpu_shader_fx_dof_frag.glsl b/source/blender/gpu/shaders/gpu_shader_fx_dof_frag.glsl
index d52ab2243fe..e9dab04de5d 100644
--- a/source/blender/gpu/shaders/gpu_shader_fx_dof_frag.glsl
+++ b/source/blender/gpu/shaders/gpu_shader_fx_dof_frag.glsl
@@ -186,7 +186,9 @@ void fifth_pass()
 	vec4 color = factors.x * color_orig + factors.y * smallblurred + factors.z * mediumblurred + factors.w * highblurred;
 
 	color /= dot(factors, vec4(1.0));
-	gl_FragColor = vec4(color.rgb, 1.0);
+	/* using original color is not correct, but use that for now because alpha of
+	 * blurred buffers uses CoC instead */
+	gl_FragColor = vec4(color.rgb, color_orig.a);
 }
 
 
diff --git a/source/blender/gpu/shaders/gpu_shader_fx_ssao_frag.glsl b/source/blender/gpu/shaders/gpu_shader_fx_ssao_frag.glsl
index b33fda92a46..86e10af8c0d 100644
--- a/source/blender/gpu/shaders/gpu_shader_fx_ssao_frag.glsl
+++ b/source/blender/gpu/shaders/gpu_shader_fx_ssao_frag.glsl
@@ -77,6 +77,7 @@ float calculate_ssao_factor(float depth)
 void main()
 {
 	float depth = texture2D(depthbuffer, uvcoordsvar.xy).r;
-	vec4 color = mix(texture2D(colorbuffer, uvcoordsvar.xy), ssao_color, calculate_ssao_factor(depth));
-	gl_FragColor = vec4(color.rgb, 1.0);
+	vec4 scene_col = texture2D(colorbuffer, uvcoordsvar.xy);
+	vec3 final_color = mix(scene_col.rgb, ssao_color.rgb, calculate_ssao_factor(depth));
+	gl_FragColor = vec4(final_color.rgb, scene_col.a);
 }