diff --git a/src/cmd/compile/internal/ssa/deadcode.go b/src/cmd/compile/internal/ssa/deadcode.go
index 4e22c965fe..47690f879e 100644
--- a/src/cmd/compile/internal/ssa/deadcode.go
+++ b/src/cmd/compile/internal/ssa/deadcode.go
@@ -54,7 +54,7 @@ func liveValues(f *Func, reachable []bool) []bool {
 	}
 
 	// Find all live values
-	var q []*Value // stack-like worklist of unscanned values
+	q := make([]*Value, 0, 64) // stack-like worklist of unscanned values
 
 	// Starting set: all control values of reachable blocks are live.
 	// Calls are live (because callee can observe the memory state).