diff --git a/gfx/drivers_shader/shader_vulkan.cpp b/gfx/drivers_shader/shader_vulkan.cpp
index 30da45f667..e7d9f307cd 100644
--- a/gfx/drivers_shader/shader_vulkan.cpp
+++ b/gfx/drivers_shader/shader_vulkan.cpp
@@ -1486,7 +1486,7 @@ Size2D Pass::get_output_size(const Size2D &original,
          break;
 
       case GLSLANG_FILTER_CHAIN_SCALE_VIEWPORT:
-         width = current_viewport.width * pass_info.scale_x;
+         width = (retroarch_get_rotation() % 2 ? current_viewport.height : current_viewport.width) * pass_info.scale_x;
          break;
 
       case GLSLANG_FILTER_CHAIN_SCALE_ABSOLUTE:
@@ -1508,7 +1508,7 @@ Size2D Pass::get_output_size(const Size2D &original,
          break;
 
       case GLSLANG_FILTER_CHAIN_SCALE_VIEWPORT:
-         height = current_viewport.height * pass_info.scale_y;
+         height = (retroarch_get_rotation() % 2 ? current_viewport.width : current_viewport.height) * pass_info.scale_y;
          break;
 
       case GLSLANG_FILTER_CHAIN_SCALE_ABSOLUTE: