diff --git a/processor/src/main/kotlin/org/ethereum/lists/chains/Main.kt b/processor/src/main/kotlin/org/ethereum/lists/chains/Main.kt
index ec670710..14018ab1 100644
--- a/processor/src/main/kotlin/org/ethereum/lists/chains/Main.kt
+++ b/processor/src/main/kotlin/org/ethereum/lists/chains/Main.kt
@@ -22,7 +22,7 @@ val chainsPath = File(dataPath, "chains")
 private val allFiles = chainsPath.listFiles() ?: error("${chainsPath.absolutePath} must contain the chain json files - but it does not")
 private val allChainFiles = allFiles.filter { !it.isDirectory }
 
-private val allIconFilesList = iconsPath.listFiles() ?:  error("${iconsPath.absolutePath} must contain the icon json files - but it does not")
+private val allIconFilesList = iconsPath.listFiles() ?: error("${iconsPath.absolutePath} must contain the icon json files - but it does not")
 private val allIconFiles = allIconFilesList.filter { !it.isDirectory }
 
 fun main(args: Array<String>) {
@@ -69,7 +69,7 @@ private fun createOutputFiles() {
         .forEach { iconLocation ->
 
             val jsonData = Klaxon().parseJsonArray(iconLocation.reader())
-            val iconName = iconLocation.toString().replace("../_data/icons/","").replace(".json","")
+            val iconName = iconLocation.toString().replace("../_data/icons/", "").replace(".json", "")
 
             val iconJson = JsonObject()
             iconJson["name"] = iconName
@@ -202,7 +202,7 @@ fun checkChain(chainFile: File, connectRPC: Boolean, verbose: Boolean = false) {
     val chainAsLong = getNumber(jsonObject, "chainId")
 
     if (chainFile.nameWithoutExtension.startsWith("eip155-")) {
-        if (chainAsLong != chainFile.nameWithoutExtension.replace("eip155-", "").toLongOrNull()) {
+        if (chainAsLong.toString() != chainFile.nameWithoutExtension.replace("eip155-", "")) {
             throw (FileNameMustMatchChainId())
         }
     } else {
@@ -314,7 +314,7 @@ fun checkChain(chainFile: File, connectRPC: Boolean, verbose: Boolean = false) {
             }
 
             if (!allowedRedFlags.contains(it))
-                throw(InvalidRedFlags(it))
+                throw (InvalidRedFlags(it))
         }
     }
 
diff --git a/processor/src/test/kotlin/org/ethereum/lists/chains/TheChainChecker.kt b/processor/src/test/kotlin/org/ethereum/lists/chains/TheChainChecker.kt
index 100c1538..58302dab 100644
--- a/processor/src/test/kotlin/org/ethereum/lists/chains/TheChainChecker.kt
+++ b/processor/src/test/kotlin/org/ethereum/lists/chains/TheChainChecker.kt
@@ -128,6 +128,13 @@ class TheChainChecker {
         checkChain(file, false)
     }
 
+    @Test(expected = FileNameMustMatchChainId::class)
+    fun shouldFailForFilenameWithLeadingZero() {
+        val file = getFile("invalid/leadingzero/eip155-01.json")
+
+        checkChain(file, false)
+    }
+
     @Test(expected = FileNameMustMatchChainId::class)
     fun shouldFailForChainNotMatchingFilename() {
         val file = getFile("invalid/eip155-3.json")
diff --git a/processor/src/test/resources/test_chains/invalid/leadingzero/eip155-01.json b/processor/src/test/resources/test_chains/invalid/leadingzero/eip155-01.json
new file mode 100644
index 00000000..63a38df4
--- /dev/null
+++ b/processor/src/test/resources/test_chains/invalid/leadingzero/eip155-01.json
@@ -0,0 +1,23 @@
+{
+  "name": "Ethereum Mainnet",
+  "shortName": "eth",
+  "chain": "ETH",
+  "chainId": 1,
+  "networkId": 1,
+  "rpc": [
+    "https://mainnet.infura.io/v3/${INFURA_API_KEY}",
+    "https://api.mycryptoapi.com/eth"
+  ],
+  "faucets": [],
+  "infoURL": "https://ethereum.org",
+  "nativeCurrency": {
+    "name": "Ether",
+    "symbol": "ETH",
+    "decimals": 18
+  },
+  "explorers": [{
+    "name": "etherscan",
+    "url": "https://etherscan.io",
+    "standard": "none"
+  }]
+}
\ No newline at end of file