diff --git a/packages/beacon-node/src/chain/bls/multithread/poolSize.ts b/packages/beacon-node/src/chain/bls/multithread/poolSize.ts
index e32c976c6687..9397f97849cd 100644
--- a/packages/beacon-node/src/chain/bls/multithread/poolSize.ts
+++ b/packages/beacon-node/src/chain/bls/multithread/poolSize.ts
@@ -4,7 +4,7 @@ try {
   if (typeof navigator !== "undefined") {
     defaultPoolSize = navigator.hardwareConcurrency ?? 4;
   } else {
-    defaultPoolSize = (await import("node:os")).cpus().length;
+    defaultPoolSize = (await import("node:os")).availableParallelism();
   }
 } catch (e) {
   defaultPoolSize = 8;
diff --git a/packages/cli/src/cmds/validator/keymanager/decryptKeystores/poolSize.ts b/packages/cli/src/cmds/validator/keymanager/decryptKeystores/poolSize.ts
index 4a3475a725cb..9219ae6d8537 100644
--- a/packages/cli/src/cmds/validator/keymanager/decryptKeystores/poolSize.ts
+++ b/packages/cli/src/cmds/validator/keymanager/decryptKeystores/poolSize.ts
@@ -4,8 +4,7 @@ try {
   if (typeof navigator !== "undefined") {
     maxPoolSize = navigator.hardwareConcurrency ?? 4;
   } else {
-    // TODO change this line to use os.availableParallelism() once we upgrade to node v20
-    maxPoolSize = (await import("node:os")).cpus().length;
+    maxPoolSize = (await import("node:os")).availableParallelism();
   }
 } catch (e) {
   maxPoolSize = 8;