diff --git a/runtime/internal/runtime/z_chan.go b/runtime/internal/runtime/z_chan.go
index ecde5e2e..55236e96 100644
--- a/runtime/internal/runtime/z_chan.go
+++ b/runtime/internal/runtime/z_chan.go
@@ -48,6 +48,7 @@ func NewChan(eltSize, cap int) *Chan {
 		ret.data = AllocU(uintptr(cap * eltSize))
 		ret.cap = cap
 	}
+	ret.mutex.Init(nil)
 	ret.cond.Init(nil)
 	return ret
 }