diff --git a/doc/user/functionality.tex b/doc/user/functionality.tex
index 5ddd51feaa..7d37bdc0fc 100644
--- a/doc/user/functionality.tex
+++ b/doc/user/functionality.tex
@@ -63,7 +63,7 @@ In addition, automatic interfaces are provided to
 
 \section{Periodic system electronic structure}
 
-A modules is available to compute energies by Gaussian Density
+A module is available to compute energies by Gaussian Density
 Functional Theory (DFT) with many local and non-local
 exchange-correlation potentials.