diff --git a/connection_manager.go b/connection_manager.go
index 83040b36..aa7961ba 100644
--- a/connection_manager.go
+++ b/connection_manager.go
@@ -14,6 +14,8 @@
 
 package ouroboros
 
+import "sync"
+
 // ConnectionManagerErrorFunc is a function that takes a connection ID and an error
 type ConnectionManagerErrorFunc func(int, error)
 
@@ -53,9 +55,10 @@ func (c ConnectionManagerTag) String() string {
 }
 
 type ConnectionManager struct {
-	config      ConnectionManagerConfig
-	hosts       []ConnectionManagerHost
-	connections map[int]*ConnectionManagerConnection
+	config           ConnectionManagerConfig
+	hosts            []ConnectionManagerHost
+	connections      map[int]*ConnectionManagerConnection
+	connectionsMutex sync.Mutex
 }
 
 type ConnectionManagerConfig struct {
@@ -107,10 +110,12 @@ func (c *ConnectionManager) AddHostsFromTopology(topology *TopologyConfig) {
 }
 
 func (c *ConnectionManager) AddConnection(connId int, conn *Connection) {
+	c.connectionsMutex.Lock()
 	c.connections[connId] = &ConnectionManagerConnection{
 		Id:   connId,
 		Conn: conn,
 	}
+	c.connectionsMutex.Unlock()
 	go func() {
 		err, ok := <-conn.ErrorChan()
 		if !ok {
@@ -123,15 +128,20 @@ func (c *ConnectionManager) AddConnection(connId int, conn *Connection) {
 }
 
 func (c *ConnectionManager) RemoveConnection(connId int) {
+	c.connectionsMutex.Lock()
 	delete(c.connections, connId)
+	c.connectionsMutex.Unlock()
 }
 
 func (c *ConnectionManager) GetConnectionById(connId int) *ConnectionManagerConnection {
+	c.connectionsMutex.Lock()
+	defer c.connectionsMutex.Unlock()
 	return c.connections[connId]
 }
 
 func (c *ConnectionManager) GetConnectionsByTags(tags ...ConnectionManagerTag) []*ConnectionManagerConnection {
 	var ret []*ConnectionManagerConnection
+	c.connectionsMutex.Lock()
 	for _, conn := range c.connections {
 		skipConn := false
 		for _, tag := range tags {
@@ -144,6 +154,7 @@ func (c *ConnectionManager) GetConnectionsByTags(tags ...ConnectionManagerTag) [
 			ret = append(ret, conn)
 		}
 	}
+	c.connectionsMutex.Unlock()
 	return ret
 }