diff --git a/source/blender/draw/engines/workbench/shaders/workbench_shadow_geom.glsl b/source/blender/draw/engines/workbench/shaders/workbench_shadow_geom.glsl
index 7418f86a58e..e97ce3b75f9 100644
--- a/source/blender/draw/engines/workbench/shaders/workbench_shadow_geom.glsl
+++ b/source/blender/draw/engines/workbench/shaders/workbench_shadow_geom.glsl
@@ -4,26 +4,20 @@
 #define USE_INVOC_EXT
 #endif
 
-#ifdef DOUBLE_MANIFOLD
-#  ifdef USE_INVOC_EXT
-#    define invoc_len 2
-#  else
-#    define vert_len 8
-#  endif
-#else
-#  ifdef USE_INVOC_EXT
-#    define invoc_len 1
+#ifdef USE_INVOC_EXT
+#  ifdef DOUBLE_MANIFOLD
+layout(lines_adjacency, invocations = 2) in;
 #  else
-#    define vert_len 4
+layout(lines_adjacency, invocations = 1) in;
 #  endif
-#endif
-
-#ifdef USE_INVOC_EXT
-layout(lines_adjacency, invocations = invoc_len) in;
 layout(triangle_strip, max_vertices = 4) out;
 #else
 layout(lines_adjacency) in;
-layout(triangle_strip, max_vertices = vert_len) out;
+#  ifdef DOUBLE_MANIFOLD
+layout(triangle_strip, max_vertices = 8) out;
+#  else
+layout(triangle_strip, max_vertices = 4) out;
+#  endif
 #endif
 
 uniform vec3 lightDirection = vec3(0.57, 0.57, -0.57);