diff --git a/var/spack/repos/builtin/packages/es-shell/package.py b/var/spack/repos/builtin/packages/es-shell/package.py
index 5486e73df0..c3093d30cd 100644
--- a/var/spack/repos/builtin/packages/es-shell/package.py
+++ b/var/spack/repos/builtin/packages/es-shell/package.py
@@ -19,3 +19,4 @@ class EsShell(AutotoolsPackage):
     version('0.9.1', sha256='b0b41fce99b122a173a06b899a4d92e5bd3cc48b227b2736159f596a58fff4ba')
 
     depends_on('readline')
+    depends_on('yacc')