diff --git a/go.mod b/go.mod
index f208383..ee8b411 100644
--- a/go.mod
+++ b/go.mod
@@ -2,8 +2,7 @@ module github.com/itzg/saml-auth-proxy
 
 require (
 	github.com/crewjam/saml v0.4.6
-	github.com/iancoleman/strcase v0.2.0 // indirect
-	github.com/itzg/go-flagsfiller v1.8.0
+	github.com/itzg/go-flagsfiller v1.9.0
 	github.com/patrickmn/go-cache v2.1.0+incompatible
 	golang.org/x/crypto v0.0.0-20210711020723-a769d52b0f97 // indirect
 )
diff --git a/go.sum b/go.sum
index 65a5d56..7c99dd4 100644
--- a/go.sum
+++ b/go.sum
@@ -13,11 +13,10 @@ github.com/golang-jwt/jwt/v4 v4.1.0 h1:XUgk2Ex5veyVFVeLm0xhusUTQybEbexJXrvPNOKkS
 github.com/golang-jwt/jwt/v4 v4.1.0/go.mod h1:/xlHOz8bRuivTWchD4jCa+NbatV+wEUSzwAxVc6locg=
 github.com/google/go-cmp v0.5.6 h1:BKbKCqvP6I+rmFHt06ZmyQtvB8xAkWdhFyr0ZUNZcxQ=
 github.com/google/go-cmp v0.5.6/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
-github.com/iancoleman/strcase v0.0.0-20191112232945-16388991a334/go.mod h1:SK73tn/9oHe+/Y0h39VT4UCxmurVJkR5NA7kMEAOgSE=
 github.com/iancoleman/strcase v0.2.0 h1:05I4QRnGpI0m37iZQRuskXh+w77mr6Z41lwQzuHLwW0=
 github.com/iancoleman/strcase v0.2.0/go.mod h1:iwCmte+B7n89clKwxIoIXy/HfoL7AsD47ZCWhYzw7ho=
-github.com/itzg/go-flagsfiller v1.8.0 h1:e6K0N4lzYQc6y9QoCMzVwpg+YHKrMVW3mqiE9bwkQ9U=
-github.com/itzg/go-flagsfiller v1.8.0/go.mod h1:mfQgTahSs4OHn8PYev2Wwi1LJXUiYiGuZVCpBLxzbYs=
+github.com/itzg/go-flagsfiller v1.9.0 h1:6Et41io46r8k5mPUdyvrgyymWvhqRInmrsYdEU34UaM=
+github.com/itzg/go-flagsfiller v1.9.0/go.mod h1:6LKRav19Dzu7PKOef3k2RHtrWKwW70KGwq5YCp4vA6s=
 github.com/jonboulle/clockwork v0.2.2 h1:UOGuzwb1PwsrDAObMuhUnj0p5ULPj8V/xJ7Kx9qUBdQ=
 github.com/jonboulle/clockwork v0.2.2/go.mod h1:Pkfl5aHPm1nk2H9h0bjmnJD/BcgbGXUBGnn1kMkgxc8=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
@@ -45,8 +44,9 @@ github.com/russellhaering/goxmldsig v1.1.1 h1:vI0r2osGF1A9PLvsGdPUAGwEIrKa4Pj5se
 github.com/russellhaering/goxmldsig v1.1.1/go.mod h1:gM4MDENBQf7M+V824SGfyIUVFWydB7n0KkEubVJl+Tw=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
-github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd0=
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/zenazn/goji v1.0.1/go.mod h1:7S9M489iMyHBNxwZnk9/EHS098H4/F6TATF2mIxtB1Q=
 golang.org/x/crypto v0.0.0-20210322153248-0c34fe9e7dc2/go.mod h1:T9bdIzuCu7OtxOm1hfPfRQxPLYneinmdGuTeoZ9dtd4=
 golang.org/x/crypto v0.0.0-20210711020723-a769d52b0f97 h1:/UOmuWzQfxxo9UtlXMwuQU8CMgg1eZXqTRwkSQJWKOI=