diff --git a/eth/backend.go b/eth/backend.go
index c669fa9743..005c94c7c8 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -126,7 +126,7 @@ func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
 	}
 	if config.NoPruning && config.TrieDirtyCache > 0 {
 		config.TrieCleanCache += config.TrieDirtyCache * 3 / 5
-		config.SnapshotCache += config.TrieDirtyCache * 3 / 5
+		config.SnapshotCache += config.TrieDirtyCache * 2 / 5
 		config.TrieDirtyCache = 0
 	}
 	log.Info("Allocated trie memory caches", "clean", common.StorageSize(config.TrieCleanCache)*1024*1024, "dirty", common.StorageSize(config.TrieDirtyCache)*1024*1024)