diff --git a/tests/integration/aof.tcl b/tests/integration/aof.tcl
index d4a556e3b..0a9f250cf 100644
--- a/tests/integration/aof.tcl
+++ b/tests/integration/aof.tcl
@@ -239,7 +239,7 @@ tags {"aof external:skip"} {
         }
     }
 
-    start_server {overrides {appendonly {yes}}} {
+    start_server {overrides {appendonly {yes} appendfsync always}} {
         test {GETEX should not append to AOF} {
             set aof [get_last_incr_aof_path r]
             r set foo bar
diff --git a/tests/unit/maxmemory.tcl b/tests/unit/maxmemory.tcl
index f8de1a410..23a9daab8 100644
--- a/tests/unit/maxmemory.tcl
+++ b/tests/unit/maxmemory.tcl
@@ -421,13 +421,19 @@ start_server {tags {"maxmemory external:skip"}} {
     } {4098}
 }
 
-start_server {tags {"maxmemory external:skip tsan:skip"}} {
+start_server {tags {"maxmemory external:skip"}} {
     test {client tracking don't cause eviction feedback loop} {
         r config set latency-tracking no
         r config set maxmemory 0
         r config set maxmemory-policy allkeys-lru
         r config set maxmemory-eviction-tenacity 100
 
+        # check if enabling multithreaded IO
+        set multithreaded 0
+        if {[r config get io-threads] > 1} {
+            set multithreaded 1
+        }
+
         # 10 clients listening on tracking messages
         set clients {}
         for {set j 0} {$j < 10} {incr j} {
@@ -465,6 +471,15 @@ start_server {tags {"maxmemory external:skip tsan:skip"}} {
         set limit [expr {$used - 40000}]
         r config set maxmemory $limit
 
+        # If multithreaded, we need to let IO threads have chance to reply output
+        # buffer, to avoid next commands causing eviction. After eviction is performed,
+        # the next command becomes ready immediately in IO threads, and now we enqueue
+        # the client to be processed in main thread’s beforeSleep without notification.
+        # However, invalidation messages generated by eviction may not have been fully
+        # delivered by that time. As a result, executing the command in beforeSleep of
+        # the event loop (running eviction) can cause additional keys to be evicted.
+        if $multithreaded { after 200 }
+
         # make sure some eviction happened
         set evicted [s evicted_keys]
         if {$::verbose} { puts "evicted: $evicted" }