diff --git a/src/acl.c b/src/acl.c
index 2202f293..269e4b40 100644
--- a/src/acl.c
+++ b/src/acl.c
@@ -29,6 +29,12 @@
 
 #include "server.h"
 
+/* =============================================================================
+ * Global state for ACLs
+ * ==========================================================================*/
+
+rax *Users; /* Table mapping usernames to user structures. */
+
 /* =============================================================================
  * Helper functions for the rest of the ACL implementation
  * ==========================================================================*/
@@ -79,6 +85,11 @@ int time_independent_strcmp(char *a, char *b) {
  * Low level ACL API
  * ==========================================================================*/
 
+/* Initialization of the ACL subsystem. */
+void ACLInit(void) {
+    Users = raxNew();
+}
+
 /* Check the username and password pair and return C_OK if they are valid,
  * otherwise C_ERR is returned and errno is set to:
  *
diff --git a/src/server.c b/src/server.c
index c297e912..48b4cdb4 100644
--- a/src/server.c
+++ b/src/server.c
@@ -2185,6 +2185,7 @@ void initServer(void) {
     if (server.cluster_enabled) clusterInit();
     replicationScriptCacheInit();
     scriptingInit(1);
+    ACLInit();
     slowlogInit();
     latencyMonitorInit();
     bioInit();
diff --git a/src/server.h b/src/server.h
index 22224f29..e120e989 100644
--- a/src/server.h
+++ b/src/server.h
@@ -1682,6 +1682,7 @@ void sendChildInfo(int process_type);
 void receiveChildInfo(void);
 
 /* acl.c -- Authentication related prototypes. */
+void ACLInit(void);
 int ACLCheckUserCredentials(robj *username, robj *password);
 unsigned long ACLGetCommandID(const char *cmdname);
 user *ACLGetUserByName(const char *name, size_t namelen);