diff --git a/Include/Aurora/IO/CompletionGroup/ICompletionGroup.hpp b/Include/Aurora/IO/CompletionGroup/ICompletionGroup.hpp
index 10521e5d..df70c60e 100644
--- a/Include/Aurora/IO/CompletionGroup/ICompletionGroup.hpp
+++ b/Include/Aurora/IO/CompletionGroup/ICompletionGroup.hpp
@@ -35,6 +35,10 @@ namespace Aurora::IO::CompletionGroup
 
         virtual AuSPtr<Loop::ILSEvent> GetTriggerLoopSource() = 0;
         virtual void TryTrigger() = 0;
+
+        // 0 = indefinite
+        virtual bool WaitForAnyMS(AuUInt32 uTimeoutOrZeroMS = 0) = 0;
+        virtual bool WaitForAllMS(AuUInt32 uTimeoutOrZeroMS = 0) = 0;
     };
 
     AUKN_SYM AuSPtr<ICompletionGroup> NewCompletionGroup();
diff --git a/Source/IO/CompletionGroup/CompletionGroup.cpp b/Source/IO/CompletionGroup/CompletionGroup.cpp
index 7bfd19de..cd43e96f 100644
--- a/Source/IO/CompletionGroup/CompletionGroup.cpp
+++ b/Source/IO/CompletionGroup/CompletionGroup.cpp
@@ -151,6 +151,30 @@ namespace Aurora::IO::CompletionGroup
         return this->anyProbablyAlwaysPresentEvent.GetLoopSource();
     }
 
+    bool CompletionGroup::WaitForAnyMS(AuUInt32 uTimeoutOrZeroMS)
+    {
+        if (auto pLoopSource = this->ToAnyLoopSource())
+        {
+            return pLoopSource->WaitOn(uTimeoutOrZeroMS);
+        }
+        else
+        {
+            return false;
+        }
+    }
+
+    bool CompletionGroup::WaitForAllMS(AuUInt32 uTimeoutOrZeroMS)
+    {
+        if (auto pLoopSource = this->ToAndLoopSource())
+        {
+            return pLoopSource->WaitOn(uTimeoutOrZeroMS);
+        }
+        else
+        {
+            return false;
+        }
+    }
+
     void CompletionGroup::TryTrigger()
     {
         if (auto pSource = GetTriggerLoopSource())
diff --git a/Source/IO/CompletionGroup/CompletionGroup.hpp b/Source/IO/CompletionGroup/CompletionGroup.hpp
index e4b9eb5b..aa91fab4 100644
--- a/Source/IO/CompletionGroup/CompletionGroup.hpp
+++ b/Source/IO/CompletionGroup/CompletionGroup.hpp
@@ -24,6 +24,9 @@ namespace Aurora::IO::CompletionGroup
         AuSPtr<Async::IWorkItem>  OnCompletion() override;
         AuSPtr<Async::IWorkItem>  OnSingleCompletion() override;
 
+        bool WaitForAnyMS(AuUInt32 uTimeoutOrZeroMS) override;
+        bool WaitForAllMS(AuUInt32 uTimeoutOrZeroMS) override;
+
         AuSPtr<Loop::ILSEvent> GetTriggerLoopSource() override;
         void TryTrigger() override;