diff --git a/source/ElectrostaticPotential.tex b/source/ElectrostaticPotential.tex
index af9a981084553d8e864af7dc91b29e11c2258411..2805bb954330fe9535add795114a2550257a173a 100644
--- a/source/ElectrostaticPotential.tex
+++ b/source/ElectrostaticPotential.tex
@@ -1,7 +1,7 @@
 \begin{modsig}{ElectrostaticPotential}
   \gimport{DeviceGeometry}
 
-  \symdef[name=electrostatic-potential]{ElectrostaticPotential}{\Psi}
+  \symdef[name=electrostatic-potential]{ElectrostaticPotential}{\psi}
   \symtest{ElectrostaticPotential}{\ElectrostaticPotential}
 \end{modsig}