@@ -38,6 +38,9 @@ func (builder *Builder) mergeConfig(userConf, imageConf *Config) {

 	if userConf.MemorySwap == 0 {

 		userConf.MemorySwap = imageConf.MemorySwap

 	}

+	if userConf.CpuShares == 0 {

+		userConf.CpuShares = imageConf.CpuShares

+	}

 	if userConf.PortSpecs == nil || len(userConf.PortSpecs) == 0 {

 		userConf.PortSpecs = imageConf.PortSpecs

 	}