diff --git a/build.gradle.kts b/build.gradle.kts
index 2b49a296..cf932ebf 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -6,8 +6,8 @@ plugins {
   `maven-publish`
   signing
 
-  kotlin("jvm") version "1.4.32"
-  id("org.jetbrains.dokka") version "1.4.32"
+  kotlin("jvm") version "1.7.10"
+  id("org.jetbrains.dokka") version "1.7.10"
 
   id("net.minecrell.licenser") version "0.4.1"
   id("org.jmailen.kotlinter") version "3.3.0"
@@ -30,7 +30,7 @@ description = "A Kotlin/Java API for generating .ts source files."
 
 // Versions
 
-val guavaVersion = "22.0"
+val guavaVersion = "31.1-jre"
 val junitJupiterVersion = "5.6.2"
 val hamcrestVersion = "1.3"
 
@@ -95,7 +95,7 @@ tasks {
 //
 
 jacoco {
-  toolVersion = "0.8.5"
+  toolVersion = "0.8.7"
 }
 
 tasks {
diff --git a/gradle.properties b/gradle.properties
index 887c6c05..ff913ecd 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,3 +1,3 @@
 org.gradle.jvmargs=-XX:MaxMetaspaceSize=512m
 
-releaseVersion=1.2.0-SNAPSHOT
+releaseVersion=1.1.3
diff --git a/src/main/java/io/outfoxx/typescriptpoet/FileSpec.kt b/src/main/java/io/outfoxx/typescriptpoet/FileSpec.kt
index e83d1953..8245e326 100644
--- a/src/main/java/io/outfoxx/typescriptpoet/FileSpec.kt
+++ b/src/main/java/io/outfoxx/typescriptpoet/FileSpec.kt
@@ -344,13 +344,13 @@ private constructor(
     fun builder(modulePath: String) = Builder(modulePath)
 
     @JvmStatic
-    fun get(moduleSpec: ModuleSpec, modulePath: String = moduleSpec.name.replace('.', '/').toLowerCase()): FileSpec =
+    fun get(moduleSpec: ModuleSpec, modulePath: String = moduleSpec.name.replace('.', '/').lowercase()): FileSpec =
       builder(modulePath)
         .apply { members.addAll(moduleSpec.members.toMutableList()) }
         .build()
 
     @JvmStatic
-    fun get(typeSpec: AnyTypeSpec, modulePath: String = typeSpec.name.replace('.', '/').toLowerCase()): FileSpec =
+    fun get(typeSpec: AnyTypeSpec, modulePath: String = typeSpec.name.replace('.', '/').lowercase()): FileSpec =
       builder(modulePath)
         .addType(typeSpec)
         .build()
diff --git a/src/main/java/io/outfoxx/typescriptpoet/Modifier.kt b/src/main/java/io/outfoxx/typescriptpoet/Modifier.kt
index c43bec62..b6c3833c 100644
--- a/src/main/java/io/outfoxx/typescriptpoet/Modifier.kt
+++ b/src/main/java/io/outfoxx/typescriptpoet/Modifier.kt
@@ -34,5 +34,5 @@ enum class Modifier {
   VAR;
 
   val keyword: String
-    get() = name.toLowerCase()
+    get() = name.lowercase()
 }
diff --git a/src/main/java/io/outfoxx/typescriptpoet/NameAllocator.kt b/src/main/java/io/outfoxx/typescriptpoet/NameAllocator.kt
index 122de861..ba4f973a 100644
--- a/src/main/java/io/outfoxx/typescriptpoet/NameAllocator.kt
+++ b/src/main/java/io/outfoxx/typescriptpoet/NameAllocator.kt
@@ -135,7 +135,7 @@ private fun toTypeScriptIdentifier(suggestion: String) = buildString {
     val validCodePoint: Int = if (Character.isJavaIdentifierPart(codePoint)) {
       codePoint
     } else {
-      '_'.toInt()
+      '_'.code
     }
     appendCodePoint(validCodePoint)
     i += Character.charCount(codePoint)
diff --git a/src/main/java/io/outfoxx/typescriptpoet/TypeName.kt b/src/main/java/io/outfoxx/typescriptpoet/TypeName.kt
index 53393109..b171afd2 100644
--- a/src/main/java/io/outfoxx/typescriptpoet/TypeName.kt
+++ b/src/main/java/io/outfoxx/typescriptpoet/TypeName.kt
@@ -240,58 +240,58 @@ sealed class TypeName {
 
   companion object {
 
-    val NULL = implicit("null")
-    val UNDEFINED = implicit("undefined")
-    val NEVER = implicit("never")
-    val VOID = implicit("void")
-    val ANY = implicit("any")
-
-    val BOOLEAN = implicit("boolean")
-    val NUMBER = implicit("number")
-    val BIGINT = implicit("bigint")
-    val STRING = implicit("string")
-    val OBJECT = implicit("object")
-    val SYMBOL = implicit("symbol")
-
-    val BOOLEAN_CLASS = implicit("Boolean")
-    val NUMBER_CLASS = implicit("Number")
-    val BIGINT_CLASS = implicit("BigInt")
-    val STRING_CLASS = implicit("String")
-    val OBJECT_CLASS = implicit("Object")
-    val SYMBOL_CLASS = implicit("Symbol")
-
-    val FUNCTION = implicit("Function")
-    val ERROR = implicit("Error")
-    val REGEXP = implicit("RegExp")
-    val MATH = implicit("Math")
-    val DATE = implicit("Date")
-
-    val SET = implicit("Set")
-    val WEAK_SET = implicit("WeakSet")
-    val MAP = implicit("Map")
-    val WEAK_MAP = implicit("WeakMap")
-
-    val ARRAY = implicit("Array")
-    val INT8_ARRAY = implicit("Int8Array")
-    val UINT8_ARRAY = implicit("Uint8Array")
-    val UINT8_CLAMPED_ARRAY = implicit("Uint8ClampedArray")
-    val INT16_ARRAY = implicit("Int16Array")
-    val UINT16_ARRAY = implicit("Uint16Array")
-    val INT32_ARRAY = implicit("Int32Array")
-    val UINT32_ARRAY = implicit("Uint32Array")
-    val FLOAT32_ARRAY = implicit("Float32Array")
-    val FLOAT64_ARRAY = implicit("Float64Array")
-    val BIG_INT64_ARRAY = implicit("BigInt64Array")
-    val BIG_UINT64_ARRAY = implicit("BigUint64Array")
-
-    val ARRAY_BUFFER = implicit("ArrayBuffer")
-    val SHARED_ARRAY_BUFFER = implicit("SharedArrayBuffer")
-    val ATOMICS = implicit("Atomics")
-    val DATA_VIEW = implicit("DataView")
-    val JSON = implicit("JSON")
-
-    val PROMISE = implicit("Promise")
-    val GENERATOR = implicit("Generator")
+    @JvmField val NULL = implicit("null")
+    @JvmField val UNDEFINED = implicit("undefined")
+    @JvmField val NEVER = implicit("never")
+    @JvmField val VOID = implicit("void")
+    @JvmField val ANY = implicit("any")
+
+    @JvmField val BOOLEAN = implicit("boolean")
+    @JvmField val NUMBER = implicit("number")
+    @JvmField val BIGINT = implicit("bigint")
+    @JvmField val STRING = implicit("string")
+    @JvmField val OBJECT = implicit("object")
+    @JvmField val SYMBOL = implicit("symbol")
+
+    @JvmField val BOOLEAN_CLASS = implicit("Boolean")
+    @JvmField val NUMBER_CLASS = implicit("Number")
+    @JvmField val BIGINT_CLASS = implicit("BigInt")
+    @JvmField val STRING_CLASS = implicit("String")
+    @JvmField val OBJECT_CLASS = implicit("Object")
+    @JvmField val SYMBOL_CLASS = implicit("Symbol")
+
+    @JvmField val FUNCTION = implicit("Function")
+    @JvmField val ERROR = implicit("Error")
+    @JvmField val REGEXP = implicit("RegExp")
+    @JvmField val MATH = implicit("Math")
+    @JvmField val DATE = implicit("Date")
+
+    @JvmField val SET = implicit("Set")
+    @JvmField val WEAK_SET = implicit("WeakSet")
+    @JvmField val MAP = implicit("Map")
+    @JvmField val WEAK_MAP = implicit("WeakMap")
+
+    @JvmField val ARRAY = implicit("Array")
+    @JvmField val INT8_ARRAY = implicit("Int8Array")
+    @JvmField val UINT8_ARRAY = implicit("Uint8Array")
+    @JvmField val UINT8_CLAMPED_ARRAY = implicit("Uint8ClampedArray")
+    @JvmField val INT16_ARRAY = implicit("Int16Array")
+    @JvmField val UINT16_ARRAY = implicit("Uint16Array")
+    @JvmField val INT32_ARRAY = implicit("Int32Array")
+    @JvmField val UINT32_ARRAY = implicit("Uint32Array")
+    @JvmField val FLOAT32_ARRAY = implicit("Float32Array")
+    @JvmField val FLOAT64_ARRAY = implicit("Float64Array")
+    @JvmField val BIG_INT64_ARRAY = implicit("BigInt64Array")
+    @JvmField val BIG_UINT64_ARRAY = implicit("BigUint64Array")
+
+    @JvmField val ARRAY_BUFFER = implicit("ArrayBuffer")
+    @JvmField val SHARED_ARRAY_BUFFER = implicit("SharedArrayBuffer")
+    @JvmField val ATOMICS = implicit("Atomics")
+    @JvmField val DATA_VIEW = implicit("DataView")
+    @JvmField val JSON = implicit("JSON")
+
+    @JvmField val PROMISE = implicit("Promise")
+    @JvmField val GENERATOR = implicit("Generator")
 
     /**
      * Any class/enum/primitive/etc type name
diff --git a/src/main/java/io/outfoxx/typescriptpoet/Utils.kt b/src/main/java/io/outfoxx/typescriptpoet/Utils.kt
index 9417d2f1..1e1dbc00 100644
--- a/src/main/java/io/outfoxx/typescriptpoet/Utils.kt
+++ b/src/main/java/io/outfoxx/typescriptpoet/Utils.kt
@@ -89,7 +89,7 @@ internal fun characterLiteralWithoutDoubleQuotes(c: Char) = when {
   c == '\"' -> "\\\"" // \u0022: double quote (")
   c == '\'' -> "'" // \u0027: single quote (')
   c == '\\' -> "\\\\" // \u005c: backslash (\)
-  isISOControl(c) -> String.format("\\u%04x", c.toInt())
+  isISOControl(c) -> String.format("\\u%04x", c.code)
   else -> c.toString()
 }