diff --git a/var/spack/repos/builtin/packages/fixesproto/package.py b/var/spack/repos/builtin/packages/fixesproto/package.py
index 92e7f494702..dd0157bd9d3 100644
--- a/var/spack/repos/builtin/packages/fixesproto/package.py
+++ b/var/spack/repos/builtin/packages/fixesproto/package.py
@@ -20,3 +20,4 @@ class Fixesproto(AutotoolsPackage, XorgPackage):
 
     depends_on("pkgconfig", type="build")
     depends_on("util-macros", type="build")
+    depends_on("xextproto")