diff --git a/doc/Eqs/fix_wall_colloid.jpg b/doc/Eqs/fix_wall_colloid.jpg
index 6c469e6185..df6b654ef5 100644
Binary files a/doc/Eqs/fix_wall_colloid.jpg and b/doc/Eqs/fix_wall_colloid.jpg differ
diff --git a/doc/Eqs/fix_wall_colloid.tex b/doc/Eqs/fix_wall_colloid.tex
index 9d3222de96..9c61af1dd2 100644
--- a/doc/Eqs/fix_wall_colloid.tex
+++ b/doc/Eqs/fix_wall_colloid.tex
@@ -4,7 +4,7 @@
 
 \begin{eqnarray}
 E &=& 144 \phi^2 \epsilon \left[ \frac{\sigma^{6}}{7560} 
-  \left(\frac{D-6R}{D^{7}} + \frac{D+8R}{(D+2R)^{7}} \right) - 
+  \left(\frac{6R-D}{D^{7}} + \frac{D+8R}{(D+2R)^{7}} \right) - 
   \frac{}{} \right. \nonumber \\
   &&\qquad \left. \frac{1}{6} \left(\frac{2R(D+R) + D(D+2R)
     \left[ \ln D - \ln (D+2R) \right]}{D(D+2R)} \right) \right]