diff --git a/src/main/java/io/emeraldpay/dshackle/upstream/ethereum/json/BlockJson.java b/src/main/java/io/emeraldpay/dshackle/upstream/ethereum/json/BlockJson.java
index fe1d25a7..2463d8e0 100644
--- a/src/main/java/io/emeraldpay/dshackle/upstream/ethereum/json/BlockJson.java
+++ b/src/main/java/io/emeraldpay/dshackle/upstream/ethereum/json/BlockJson.java
@@ -21,8 +21,6 @@ import java.util.Objects;
 @JsonSerialize(using = BlockJsonSerializer.class)
 public class BlockJson<T extends TransactionRefJson> implements Serializable {
 
-    //TODO nonce or sealFields
-
     /**
      * the block number. null when its pending block.
      */
@@ -240,11 +238,11 @@ public class BlockJson<T extends TransactionRefJson> implements Serializable {
     }
 
     public HexData getExtraData() {
-        if (extraData != null) {
-            return extraData;
-        } else {
-            return HexData.empty();
-        }
+        return Objects.requireNonNullElseGet(extraData, HexData::empty);
+    }
+
+    public boolean checkExtraData() {
+        return extraData != null;
     }
 
     public void setExtraData(HexData extraData) {
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/ThrottledLogger.kt b/src/main/kotlin/io/emeraldpay/dshackle/ThrottledLogger.kt
new file mode 100644
index 00000000..88dda0bb
--- /dev/null
+++ b/src/main/kotlin/io/emeraldpay/dshackle/ThrottledLogger.kt
@@ -0,0 +1,25 @@
+package io.emeraldpay.dshackle
+
+import com.github.benmanes.caffeine.cache.Caffeine
+import org.slf4j.Logger
+import java.time.Duration
+
+class ThrottledLogger {
+    companion object {
+
+        private val cache = Caffeine.newBuilder()
+            .expireAfterWrite(Duration.ofMinutes(1))
+            .build<String, Boolean>()
+
+        fun log(log: Logger, msg: String) {
+            log(log, msg, msg)
+        }
+
+        fun log(log: Logger, category: String, msg: String) {
+            if (cache.getIfPresent(category) == null) {
+                log.warn(msg)
+                cache.put(category, true)
+            }
+        }
+    }
+}
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumDirectReader.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumDirectReader.kt
index 279a0ce0..9ccaeca9 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumDirectReader.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumDirectReader.kt
@@ -3,6 +3,7 @@ package io.emeraldpay.dshackle.upstream.ethereum
 import com.fasterxml.jackson.databind.ObjectMapper
 import io.emeraldpay.dshackle.Defaults
 import io.emeraldpay.dshackle.Global
+import io.emeraldpay.dshackle.ThrottledLogger
 import io.emeraldpay.dshackle.cache.Caches
 import io.emeraldpay.dshackle.cache.CurrentBlockCache
 import io.emeraldpay.dshackle.data.BlockContainer
@@ -160,6 +161,9 @@ class EthereumDirectReader(
             .retryWhen(Retry.fixedDelay(3, Duration.ofMillis(200)))
             .flatMap { result ->
                 val block = objectMapper.readValue(result.data, BlockJson::class.java) as BlockJson<TransactionRefJson>?
+                if (block?.checkExtraData() == false) {
+                    ThrottledLogger.log(log, "${up.getId()} recieved block with empty extradata from direct reader")
+                }
                 if (block == null) {
                     Mono.empty()
                 } else {
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumWsHead.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumWsHead.kt
index 81d05a7b..54896dad 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumWsHead.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumWsHead.kt
@@ -18,6 +18,7 @@ package io.emeraldpay.dshackle.upstream.ethereum
 
 import io.emeraldpay.dshackle.Global
 import io.emeraldpay.dshackle.SilentException
+import io.emeraldpay.dshackle.ThrottledLogger
 import io.emeraldpay.dshackle.data.BlockContainer
 import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.reader.Reader
@@ -89,7 +90,11 @@ class EthereumWsHead(
     fun listenNewHeads(): Flux<BlockContainer> {
         return subscribe()
             .map {
-                Global.objectMapper.readValue(it, BlockJson::class.java) as BlockJson<TransactionRefJson>
+                val block = Global.objectMapper.readValue(it, BlockJson::class.java) as BlockJson<TransactionRefJson>
+                if (!block.checkExtraData() && skipEnhance) {
+                    ThrottledLogger.log(log, "$upstreamId recieved block with empty extradata through ws subscription")
+                }
+                return@map block
             }
             .flatMap { block ->
                 // newHeads returns incomplete blocks, i.e. without some fields and without transaction hashes,
@@ -115,7 +120,13 @@ class EthereumWsHead(
                                         }
                                     }
                                     .flatMap(JsonRpcResponse::requireResult)
-                                    .map { BlockContainer.fromEthereumJson(it, upstreamId) }
+                                    .map {
+                                        val parsedBlock = BlockContainer.fromEthereumJson(it, upstreamId)
+                                        if (parsedBlock.parsed is BlockJson<*> && !parsedBlock.parsed.checkExtraData() && !skipEnhance) {
+                                            ThrottledLogger.log(log, "$upstreamId recieved block with empty extradata from block enrichment")
+                                        }
+                                        return@map parsedBlock
+                                    }
                             }
                         },
                         headScheduler