diff --git a/data/shaders/diffuseenvmap.frag b/data/shaders/diffuseenvmap.frag
index 011f3a2d9..a1991b8a8 100644
--- a/data/shaders/diffuseenvmap.frag
+++ b/data/shaders/diffuseenvmap.frag
@@ -52,7 +52,7 @@ void main(void)
     float specval = pow(texture(ntex, uv).z, 2.);
     // From http://graphics.cs.williams.edu/papers/EnvMipReport2013/
     int texSize = textureSize(tex, 0).x;
-    float lodval = clamp(log2(texSize * sqrt(3)) - .5 * log2(specval + 1), 0., 10.);
+    float lodval = clamp(log2(texSize * sqrt(3.)) - .5 * log2(specval + 1.), 0., 10.);
     vec4 specular = textureLod(tex, sampleDirection, lodval);
     Spec = max(specular, vec4(0.));
 }