diff --git a/server/backend/ldap.go b/server/backend/ldap.go
index d28c5537..904daa2f 100644
--- a/server/backend/ldap.go
+++ b/server/backend/ldap.go
@@ -1196,7 +1196,10 @@ func (l *LDAPConnection) modifyAdd(ldapRequest *LDAPRequest) (err error) {
 // Then it sets the state of the connection to global.LDAPStateFree.
 // Finally, it unlocks the state of the connection using the ldapPool.conn[index].Mu.Unlock() method.
 func sendLDAPReplyAndUnlockState[T PoolRequest[T]](ldapPool *LDAPPool, index int, request T, ldapReply *LDAPReply) {
-	request.GetLDAPReplyChan() <- ldapReply
+	select {
+	case request.GetLDAPReplyChan() <- ldapReply:
+	default:
+	}
 
 	ldapPool.conn[index].Mu.Lock()
 
@@ -1294,7 +1297,10 @@ func (l *LDAPPool) proccessLookupRequest(index int, ldapRequest *LDAPRequest, ld
 	ldapReply := &LDAPReply{}
 
 	if ldapReply.Err = l.checkConnection(ldapRequest.GUID, index); ldapReply.Err != nil {
-		ldapRequest.LDAPReplyChan <- ldapReply
+		select {
+		case ldapRequest.LDAPReplyChan <- ldapReply:
+		default:
+		}
 
 		return
 	}
@@ -1356,7 +1362,10 @@ func LDAPMainWorker(ctx context.Context) {
 		case ldapRequest := <-LDAPRequestChan:
 			// Check that we have enough idle connections.
 			if err := ldapPool.setIdleConnections(true); err != nil {
-				ldapRequest.LDAPReplyChan <- &LDAPReply{Err: err}
+				select {
+				case ldapRequest.LDAPReplyChan <- &LDAPReply{Err: err}:
+				default:
+				}
 			}
 
 			ldapPool.handleLookupRequest(ldapRequest, &ldapWaitGroup)
@@ -1405,7 +1414,10 @@ func (l *LDAPPool) processAuthRequest(index int, ldapAuthRequest *LDAPAuthReques
 	ldapReply := &LDAPReply{}
 
 	if ldapReply.Err = l.checkConnection(ldapAuthRequest.GUID, index); ldapReply.Err != nil {
-		ldapAuthRequest.LDAPReplyChan <- ldapReply
+		select {
+		case ldapAuthRequest.LDAPReplyChan <- ldapReply:
+		default:
+		}
 
 		return
 	}
@@ -1460,7 +1472,10 @@ func LDAPAuthWorker(ctx context.Context) {
 		case ldapAuthRequest := <-LDAPAuthRequestChan:
 			// Check that we have enough idle connections.
 			if err := ldapPool.setIdleConnections(false); err != nil {
-				ldapAuthRequest.LDAPReplyChan <- &LDAPReply{Err: err}
+				select {
+				case ldapAuthRequest.LDAPReplyChan <- &LDAPReply{Err: err}:
+				default:
+				}
 			}
 
 			ldapPool.handleAuthRequest(ldapAuthRequest, &ldapWaitGroup)
@@ -1512,7 +1527,13 @@ func LuaLDAPSearch(ctx context.Context) lua.LGFunction {
 
 		ldapRequest := createLDAPRequest(fieldValues, scope, ctx)
 
-		LDAPRequestChan <- ldapRequest
+		select {
+		case LDAPRequestChan <- ldapRequest:
+		default:
+			L.RaiseError(errors.ErrClosedChannel.Error())
+
+			return 1
+		}
 
 		return processReply(L, ldapRequest.GetLDAPReplyChan())
 	}
diff --git a/server/backend/lua.go b/server/backend/lua.go
index 220df3d8..1a4a548b 100644
--- a/server/backend/lua.go
+++ b/server/backend/lua.go
@@ -403,8 +403,11 @@ func processError(err error, luaRequest *LuaRequest, logs *lualib.CustomLogKeyVa
 		global.LogKeyError, err,
 	)
 
-	luaRequest.LuaReplyChan <- &lualib.LuaBackendResult{
+	select {
+	case luaRequest.LuaReplyChan <- &lualib.LuaBackendResult{
 		Err:  err,
 		Logs: logs,
+	}:
+	default:
 	}
 }
diff --git a/server/core/ldap.go b/server/core/ldap.go
index 36d7f62f..a24d7354 100644
--- a/server/core/ldap.go
+++ b/server/core/ldap.go
@@ -175,7 +175,11 @@ func ldapPassDB(auth *AuthState) (passDBResult *PassDBResult, err error) {
 	}
 
 	// Find user with account status enabled
-	backend.LDAPRequestChan <- ldapRequest
+	select {
+	case backend.LDAPRequestChan <- ldapRequest:
+	default:
+		return passDBResult, errors.ErrClosedChannel
+	}
 
 	ldapReply = <-ldapReplyChan
 
@@ -234,7 +238,11 @@ func ldapPassDB(auth *AuthState) (passDBResult *PassDBResult, err error) {
 			HTTPClientContext: auth.HTTPClientContext,
 		}
 
-		backend.LDAPAuthRequestChan <- ldapUserBindRequest
+		select {
+		case backend.LDAPAuthRequestChan <- ldapUserBindRequest:
+		default:
+			return passDBResult, errors.ErrClosedChannel
+		}
 
 		ldapReply = <-ldapReplyChan
 
@@ -333,7 +341,11 @@ func ldapAccountDB(auth *AuthState) (accounts AccountList, err error) {
 	}
 
 	// Find user with account status enabled
-	backend.LDAPRequestChan <- ldapRequest
+	select {
+	case backend.LDAPRequestChan <- ldapRequest:
+	default:
+		return accounts, errors.ErrClosedChannel
+	}
 
 	ldapReply = <-ldapReplyChan
 
@@ -424,7 +436,11 @@ func ldapAddTOTPSecret(auth *AuthState, totp *TOTPSecret) (err error) {
 	ldapRequest.ModifyAttributes = make(backend.LDAPModifyAttributes, 2)
 	ldapRequest.ModifyAttributes[configField] = []string{totp.getValue()}
 
-	backend.LDAPRequestChan <- ldapRequest
+	select {
+	case backend.LDAPRequestChan <- ldapRequest:
+	default:
+		return errors.ErrClosedChannel
+	}
 
 	ldapReply = <-ldapReplyChan
 
diff --git a/server/core/lua.go b/server/core/lua.go
index c882d778..6452c2ba 100644
--- a/server/core/lua.go
+++ b/server/core/lua.go
@@ -18,6 +18,7 @@ package core
 import (
 	"github.com/croessner/nauthilus/server/backend"
 	"github.com/croessner/nauthilus/server/config"
+	"github.com/croessner/nauthilus/server/errors"
 	"github.com/croessner/nauthilus/server/global"
 	"github.com/croessner/nauthilus/server/lualib"
 	"github.com/croessner/nauthilus/server/stats"
@@ -87,7 +88,11 @@ func luaPassDB(auth *AuthState) (passDBResult *PassDBResult, err error) {
 		},
 	}
 
-	backend.LuaRequestChan <- luaRequest
+	select {
+	case backend.LuaRequestChan <- luaRequest:
+	default:
+		return passDBResult, errors.ErrClosedChannel
+	}
 
 	luaBackendResult = <-luaReplyChan
 
@@ -175,7 +180,11 @@ func luaAccountDB(auth *AuthState) (accounts AccountList, err error) {
 		},
 	}
 
-	backend.LuaRequestChan <- luaRequest
+	select {
+	case backend.LuaRequestChan <- luaRequest:
+	default:
+		return accounts, errors.ErrClosedChannel
+	}
 
 	luaBackendResult = <-luaReplyChan
 
@@ -229,7 +238,11 @@ func luaAddTOTPSecret(auth *AuthState, totp *TOTPSecret) (err error) {
 		},
 	}
 
-	backend.LuaRequestChan <- luaRequest
+	select {
+	case backend.LuaRequestChan <- luaRequest:
+	default:
+		return errors.ErrClosedChannel
+	}
 
 	luaBackendResult = <-luaReplyChan
 
diff --git a/server/errors/errors.go b/server/errors/errors.go
index 725b5a34..36b1eba8 100644
--- a/server/errors/errors.go
+++ b/server/errors/errors.go
@@ -144,6 +144,7 @@ var (
 // common.
 
 var (
+	ErrClosedChannel  = errors.New("channel closed")
 	ErrNoPassDBResult = errors.New("no pass Database result")
 	ErrUnknownCause   = errors.New("something went wrong")
 )