diff --git a/user.go b/user.go
index 392f788..5459aab 100644
--- a/user.go
+++ b/user.go
@@ -157,9 +157,9 @@ type network struct {
 func newNetwork(user *user, record *database.Network, channels []database.Channel) *network {
 	logger := &prefixLogger{user.logger, fmt.Sprintf("network %q: ", record.GetName())}
 
-	// Initialize maps with the no-op case-mapping to avoid collisions: we
-	// don't know which case-mapping will be used by the upstream server yet
-	cm := xirc.CaseMappingNone
+	// Initialize maps with the most strict case-mapping to avoid collisions:
+	// we don't know which case-mapping will be used by the upstream server yet
+	cm := xirc.CaseMappingASCII
 
 	m := xirc.NewCaseMappingMap[*database.Channel](cm)
 	for _, ch := range channels {
diff --git a/xirc/casemapping.go b/xirc/casemapping.go
index 4f8c7b0..e59d898 100644
--- a/xirc/casemapping.go
+++ b/xirc/casemapping.go
@@ -1,9 +1,5 @@
 package xirc
 
-func casemapNone(name string) string {
-	return name
-}
-
 // CasemapASCII of name is the canonical representation of name according to the
 // ascii casemapping.
 func casemapASCII(name string) string {
@@ -57,7 +53,6 @@ func casemapRFC1459Strict(name string) string {
 type CaseMapping func(string) string
 
 var (
-	CaseMappingNone          CaseMapping = casemapNone
 	CaseMappingASCII         CaseMapping = casemapASCII
 	CaseMappingRFC1459       CaseMapping = casemapRFC1459
 	CaseMappingRFC1459Strict CaseMapping = casemapRFC1459Strict