diff --git a/unixodbc/unixodbc.spec b/unixodbc/unixodbc.spec
index 18f4124b6f..ce90ff6b23 100644
--- a/unixodbc/unixodbc.spec
+++ b/unixodbc/unixodbc.spec
@@ -40,7 +40,7 @@ Source0:      http://www.unixodbc.org/unixODBC-%{version}.tar.gz
 #   build information
 Prefix:       %{l_prefix}
 BuildRoot:    %{l_buildroot}
-BuildPreReq:  OpenPKG, openpkg >= 0.9-20011025.0, make, gcc
+BuildPreReq:  OpenPKG, openpkg >= 0.9-20011025.0, make, gcc, flex
 PreReq:       OpenPKG, openpkg >= 0.9-20011025.0
 AutoReq:      no
 AutoReqProv:  no