diff --git a/e2e/polymorphism/src/test/resources/sample.yaml b/e2e/polymorphism/src/test/resources/sample.yaml
index eea6eec..405e390 100644
--- a/e2e/polymorphism/src/test/resources/sample.yaml
+++ b/e2e/polymorphism/src/test/resources/sample.yaml
@@ -5,7 +5,9 @@ info:
   version: 0.1.9
 
 servers:
-  - url: http://api.example.com/v1
+  - url: http://api.example.com:80/v1
+    description: Optional server description, e.g. Main (production) server
+  - url: http://172.0.0.1:8080/v1
     description: Optional server description, e.g. Main (production) server
   - url: http://staging-api.example.com
     description: Optional server description, e.g. Internal staging server for testing
diff --git a/gradle-plugin/processor/src/main/kotlin/com/dshatz/openapi2ktor/generators/clients/KtorClientGenerator.kt b/gradle-plugin/processor/src/main/kotlin/com/dshatz/openapi2ktor/generators/clients/KtorClientGenerator.kt
index 5fdb075..82ade73 100644
--- a/gradle-plugin/processor/src/main/kotlin/com/dshatz/openapi2ktor/generators/clients/KtorClientGenerator.kt
+++ b/gradle-plugin/processor/src/main/kotlin/com/dshatz/openapi2ktor/generators/clients/KtorClientGenerator.kt
@@ -39,6 +39,10 @@ class KtorClientGenerator(override val typeStore: TypeStore, val packages: Packa
     private lateinit var securitySchemes: Map<String, SecurityScheme>
     private var globalSecurityRequirements: List<String> = emptyList()
 
+    private val ignoreUnknownJson = Json {
+        ignoreUnknownKeys = true
+    }
+
     override fun generate(schema: OpenApi3): List<FileSpec> {
         processSecurity(schema)
         val serversEnum = generateServersEnum(schema)
@@ -60,20 +64,6 @@ class KtorClientGenerator(override val typeStore: TypeStore, val packages: Packa
         val pathTree = buildPathTree(schema.paths)
         val clientSpecs = mutableListOf<FileSpec>()
         pathTree.generateClients("", clientSpecs)
-        /*val clients = pathTree.children.map { node ->
-            val path = node.path.substringAfter('/')
-            val prefix = if (path.toIntOrNull() != null) {
-                // probably a version path (e.g. /3/...)
-                "v$path"
-            } else path
-
-            val allPaths = node.getAllPaths()
-            generateClientForPackagePrefix(schema, prefix, allPaths)
-        }*/
-        /*val clients = schema.paths.entries.groupBy { it.key.drop(1).substringBefore("/") }
-            .mapValues { (firstSegment, paths) ->
-                generateClientForPackagePrefix(schema, firstSegment, paths.associate { it.key to it.value})
-            }*/
         return clientSpecs + serversEnum
     }
 
@@ -88,9 +78,7 @@ class KtorClientGenerator(override val typeStore: TypeStore, val packages: Packa
 
     private fun processSecurity(schema: OpenApi3) {
         if (schema.securitySchemes.isNotEmpty()) {
-            securitySchemes = Json {
-                ignoreUnknownKeys = true
-            }.decodeFromString<Map<String, SecurityScheme>>(Overlay.of(schema.securitySchemes).toJson().toString())
+            securitySchemes = ignoreUnknownJson.decodeFromString<Map<String, SecurityScheme>>(Overlay.of(schema.securitySchemes).toJson().toString())
                 .mapValues { (_, scheme) ->
                     if (scheme is ApiKey && scheme.bearerFormat == "bearer") {
                         // Some strange syntax for defining bearer.
@@ -104,8 +92,13 @@ class KtorClientGenerator(override val typeStore: TypeStore, val packages: Packa
 
     private fun generateServersEnum(schema: OpenApi3): FileSpec {
         val enumNames = schema.servers.associateWith {
-            it.url.substringAfter("//").substringBefore("/")
+            it.url.substringAfter("//") // after scheme
+                .substringBefore("/") // before first slash = domain name with port
+                .substringBefore(":") // domain name without port
                 .split(".", "-").joinToString("_") { it.uppercase() }
+                .let { name ->
+                    if (name.first().isDigit()) "IP_$name" else name
+                }
         }
         val enum = TypeSpec.enumBuilder(ClassName(packages.client, "Servers"))
             .primaryConstructor(FunSpec.constructorBuilder().addParameter("url", String::class).build())
@@ -225,9 +218,7 @@ class KtorClientGenerator(override val typeStore: TypeStore, val packages: Packa
         val funcSpecs: List<EndpointTools> = paths.flatMap { (pathString, path) ->
             path.operations.map { (verb, operation) ->
                 val pathLevelSecurity = operation.securityRequirements.flatMap { it.requirements.keys }
-                val security = if (pathLevelSecurity.isEmpty())
-                    globalSecurityRequirements
-                else pathLevelSecurity
+                val security = pathLevelSecurity.ifEmpty { globalSecurityRequirements }
                 val statusToResponseType = operation.responses.mapValues { (statusCode, response) ->
                     val resposneRef = Overlay.of(response).jsonReference
                     val responseModel = typeStore.getResponseMapping(TypeStore.PathId(pathString, verb))[statusCode.toInt()]?.type