diff --git a/mailx.spec b/mailx.spec
index e5d8b25..8970f29 100644
--- a/mailx.spec
+++ b/mailx.spec
@@ -22,6 +22,7 @@ BuildRequires:  krb5-devel
 BuildRequires:  man
 BuildRequires:  openssl-devel
 BuildRequires:  pcre
+BuildRequires:  pkg-config
 BuildRequires:  postfix
 BuildRequires:  pkgconfig(openssl)
 Url:            http://heirloom.sourceforge.net/mailx.html