diff --git a/neo/renderer/tr_render.cpp b/neo/renderer/tr_render.cpp
index 92cbca03..518cd051 100644
--- a/neo/renderer/tr_render.cpp
+++ b/neo/renderer/tr_render.cpp
@@ -694,6 +694,10 @@ void RB_CreateSingleDrawInteractions( const drawSurf_t *surf, void (*DrawInterac
 	const idMaterial	*lightShader = vLight->lightShader;
 	const float			*lightRegs = vLight->shaderRegisters;
 	drawInteraction_t	inter;
+	inter.diffuseMatrix[0].Zero();
+	inter.diffuseMatrix[1].Zero();
+	inter.specularMatrix[0].Zero();
+	inter.specularMatrix[1].Zero();
 
 	if ( r_skipInteractions.GetBool() || !surf->geo || !surf->geo->ambientCache ) {
 		return;