diff --git a/source/blender/draw/engines/eevee/shaders/volumetric_frag.glsl b/source/blender/draw/engines/eevee/shaders/volumetric_frag.glsl
index 90c36801dd5..a98ff4b1842 100644
--- a/source/blender/draw/engines/eevee/shaders/volumetric_frag.glsl
+++ b/source/blender/draw/engines/eevee/shaders/volumetric_frag.glsl
@@ -20,7 +20,7 @@ layout(location = 1) out vec4 volumeExtinction;
 layout(location = 2) out vec4 volumeEmissive;
 layout(location = 3) out vec4 volumePhase;
 
-int attr_id;
+int attr_id = 0;
 
 #ifndef CLEAR
 GlobalData init_globals(void)