diff --git a/pymule/plot.py b/pymule/plot.py
index 5c9cebbc32062df2b5a9145bb23c72ab9569f144..2888f5e796c47eeec16e77b1ef0b31007989c378 100644
--- a/pymule/plot.py
+++ b/pymule/plot.py
@@ -12,7 +12,8 @@ rc('text', usetex=True)
 rc('text.latex', preamble="\n".join([
     '\\usepackage{amsmath}',
     '\\usepackage{upgreek}',
-    '\\newcommand{\\D}{\mathrm{d}}'
+    '\\newcommand{\\Einv}{E\\hspace*{-6pt}/}',
+    '\\newcommand{\\D}{\\mathrm{d}}'
 ]))