diff --git a/sigar_interface.go b/sigar_interface.go
index e457c9fab..431e109c3 100644
--- a/sigar_interface.go
+++ b/sigar_interface.go
@@ -11,6 +11,7 @@ type Sigar interface {
 	CollectCpuStats(collectionInterval time.Duration) (<-chan Cpu, chan<- struct{})
 	GetLoadAverage() (LoadAverage, error)
 	GetMem() (Mem, error)
+	GetMemIgnoringCGroups() (Mem, error)
 	GetSwap() (Swap, error)
 	GetFileSystemUsage(string) (FileSystemUsage, error)
 }