diff --git a/indra/llrender/llrender.cpp b/indra/llrender/llrender.cpp
index ec6bed8e677119c3cd6d656533718f5831ebf0ad..9fca37e472b291ff27e88cfb62fcd6c64da2109c 100644
--- a/indra/llrender/llrender.cpp
+++ b/indra/llrender/llrender.cpp
@@ -1242,7 +1242,7 @@ void LLRender::syncLightState()
         shader->uniform4fv(LLShaderMgr::LIGHT_POSITION, LL_NUM_LIGHT_UNITS, position[0].mV);
         shader->uniform3fv(LLShaderMgr::LIGHT_DIRECTION, LL_NUM_LIGHT_UNITS, direction[0].mV);
         shader->uniform4fv(LLShaderMgr::LIGHT_ATTENUATION, LL_NUM_LIGHT_UNITS, attenuation[0].mV);
-        shader->uniform4fv(LLShaderMgr::LIGHT_DIFFUSE, LL_NUM_LIGHT_UNITS, light_diffuse[0].mV);
+        shader->uniform3fv(LLShaderMgr::LIGHT_DIFFUSE, LL_NUM_LIGHT_UNITS, light_diffuse[0].mV);
         shader->uniform4fv(LLShaderMgr::LIGHT_AMBIENT, 1, mAmbientLightColor.mV);
         shader->uniform1i(LLShaderMgr::SUN_UP_FACTOR, sun_primary[0] ? 1 : 0);
         shader->uniform4fv(LLShaderMgr::AMBIENT, 1, mAmbientLightColor.mV);