diff --git a/indra/newview/llreflectionmapmanager.cpp b/indra/newview/llreflectionmapmanager.cpp
index 5729a85b7afc94e8c7dc86ab66fd3a9fc24fde9e..4a0a47d711c584def7e7994d3e81a967224f57c7 100644
--- a/indra/newview/llreflectionmapmanager.cpp
+++ b/indra/newview/llreflectionmapmanager.cpp
@@ -1017,7 +1017,7 @@ void LLReflectionMapManager::initReflectionMaps()
         mTexture->allocate(mProbeResolution, 3, mReflectionProbeCount + 2);
 
         mIrradianceMaps = new LLCubeMapArray();
-        mIrradianceMaps->allocate(LL_IRRADIANCE_MAP_RESOLUTION, 4, mReflectionProbeCount, FALSE);
+        mIrradianceMaps->allocate(LL_IRRADIANCE_MAP_RESOLUTION, 3, mReflectionProbeCount, FALSE);
     }
 
     if (mVertexBuffer.isNull())