diff --git a/core/go.mod b/core/go.mod
index 647b5f3ab..3fadcbd63 100644
--- a/core/go.mod
+++ b/core/go.mod
@@ -1,6 +1,8 @@
 module github.com/open-feature/flagd/core
 
-go 1.20
+go 1.21
+
+toolchain go1.21.5
 
 require (
 	buf.build/gen/go/open-feature/flagd/connectrpc/go v1.12.0-20231031123731-ac2ec0f39838.1
@@ -35,7 +37,7 @@ require (
 	golang.org/x/exp v0.0.0-20231127185646-65229373498e
 	golang.org/x/mod v0.14.0
 	golang.org/x/net v0.19.0
-	golang.org/x/sync v0.5.0
+	golang.org/x/sync v0.6.0
 	google.golang.org/grpc v1.60.1
 	google.golang.org/protobuf v1.32.0
 	gopkg.in/yaml.v3 v3.0.1
diff --git a/core/go.sum b/core/go.sum
index 390647be6..e8a48f142 100644
--- a/core/go.sum
+++ b/core/go.sum
@@ -897,6 +897,8 @@ golang.org/x/sync v0.0.0-20220929204114-8fcdb60fdcc0/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.5.0 h1:60k92dhOjHxJkrqnwsfl8KuaHbn/5dl0lUPUklKo3qE=
 golang.org/x/sync v0.5.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
+golang.org/x/sync v0.6.0 h1:5BMeUDZ7vkXGfEr1x9B4bRcTH4lpkTkpdh0T/J+qjbQ=
+golang.org/x/sync v0.6.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190312061237-fead79001313/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=