diff --git a/var/spack/repos/builtin/packages/the_silver_searcher/package.py b/var/spack/repos/builtin/packages/the_silver_searcher/package.py
index e4020b6766..30f06354bf 100644
--- a/var/spack/repos/builtin/packages/the_silver_searcher/package.py
+++ b/var/spack/repos/builtin/packages/the_silver_searcher/package.py
@@ -9,6 +9,7 @@ class TheSilverSearcher(Package):
 
     depends_on('pcre')
     depends_on('xz')
+    depends_on('pkg-config')
 
     def install(self, spec, prefix):
         configure("--prefix=%s" % prefix)