diff --git a/src/coreclr/vm/ceemain.cpp b/src/coreclr/vm/ceemain.cpp
index f3a8796aa12f36..9f9ffc56530b0f 100644
--- a/src/coreclr/vm/ceemain.cpp
+++ b/src/coreclr/vm/ceemain.cpp
@@ -1796,7 +1796,7 @@ static void OsAttachThread(void* thread)
 //  thread        - thread to detach
 // Return:
 //  true if the thread was detached, false if there was no attached thread
-bool OsDetachThread(void* thread)
+void OsDetachThread(void* thread)
 {
     ASSERT(g_flsIndex != FLS_OUT_OF_INDEXES);
     void* threadFromCurrentFiber = FlsGetValue(g_flsIndex);
@@ -1805,7 +1805,7 @@ bool OsDetachThread(void* thread)
     {
         // we've seen this thread, but not this fiber.  It must be a "foreign" fiber that was
         // borrowing this thread.
-        return false;
+        return;
     }
 
     if (threadFromCurrentFiber != thread)
@@ -1814,7 +1814,6 @@ bool OsDetachThread(void* thread)
     }
 
     FlsSetValue(g_flsIndex, NULL);
-    return true;
 }
 
 void EnsureTlsDestructionMonitor()
diff --git a/src/coreclr/vm/ceemain.h b/src/coreclr/vm/ceemain.h
index 69ba92d692d6d2..120082d30572ca 100644
--- a/src/coreclr/vm/ceemain.h
+++ b/src/coreclr/vm/ceemain.h
@@ -48,7 +48,7 @@ void ThreadDetaching();
 void EnsureTlsDestructionMonitor();
 #ifdef TARGET_WINDOWS
 void InitFlsSlot();
-bool OsDetachThread(void* thread);
+void OsDetachThread(void* thread);
 #endif
 
 void SetLatchedExitCode (INT32 code);