diff --git a/src/Compiler.ts b/src/Compiler.ts
index 73f2c01f4..7d01f0ea9 100644
--- a/src/Compiler.ts
+++ b/src/Compiler.ts
@@ -155,10 +155,11 @@ function emitFilesAndReportErrors(program: ts.Program): number {
 }
 
 export function createTranspiler(checker: ts.TypeChecker,
-                                 options: ts.CompilerOptions,
+                                 options: CompilerOptions,
                                  sourceFile: ts.SourceFile): LuaTranspiler {
     let luaTargetTranspiler: LuaTranspiler;
-    switch (options.luaTarget) {
+    const target = options.luaTarget ? options.luaTarget.toLowerCase() : "";
+    switch (target) {
         case LuaTarget.Lua51:
             luaTargetTranspiler = new LuaTranspiler51(checker, options, sourceFile);
             break;
diff --git a/src/Errors.ts b/src/Errors.ts
index 7a32f3926..9c0319904 100644
--- a/src/Errors.ts
+++ b/src/Errors.ts
@@ -34,6 +34,9 @@ export class TSTLErrors {
     public static InvalidExtensionMetaExtension = (node: ts.Node) =>
         new TranspileError(`Cannot use both '!Extension' and '!MetaExtension' decorators on the same class.`, node)
 
+    public static InvalidNewExpressionOnExtension = (node: ts.Node) =>
+        new TranspileError(`Cannot construct classes with decorator '!Extension' or '!MetaExtension'.`, node)
+
     public static InvalidPropertyCall = (node: ts.Node) =>
         new TranspileError(`Tried to transpile a non-property call as property call.`, node)
 
diff --git a/src/Transpiler.ts b/src/Transpiler.ts
index 1ba744de7..3a428a1fb 100644
--- a/src/Transpiler.ts
+++ b/src/Transpiler.ts
@@ -15,10 +15,11 @@ export enum LuaTarget {
     Lua51 = "5.1",
     Lua52 = "5.2",
     Lua53 = "5.3",
-    LuaJIT = "JIT",
+    LuaJIT = "jit",
 }
 
 export enum LuaLibFeature {
+    ArrayConcat = "ArrayConcat",
     ArrayEvery = "ArrayEvery",
     ArrayFilter = "ArrayFilter",
     ArrayForEach = "ArrayForEach",
@@ -315,14 +316,25 @@ export abstract class LuaTranspiler {
 
         const imports = node.importClause.namedBindings;
 
+        const requireKeyword = "require";
+
         if (ts.isNamedImports(imports)) {
             const fileImportTable = path.basename(importPathWithoutQuotes) + this.importCount;
             const resolvedImportPath = this.getImportPath(importPathWithoutQuotes);
 
-            let result = `local ${fileImportTable} = require(${resolvedImportPath})\n`;
+            let result = `local ${fileImportTable} = ${requireKeyword}(${resolvedImportPath})\n`;
             this.importCount++;
 
-            imports.elements.forEach(element => {
+            const filteredElements = imports.elements.filter(e => {
+                const decorators = tsHelper.getCustomDecorators(this.checker.getTypeAtLocation(e), this.checker);
+                return !decorators.has(DecoratorKind.Extension) && !decorators.has(DecoratorKind.MetaExtension);
+            });
+
+            if (filteredElements.length === 0) {
+                return "";
+            }
+
+            filteredElements.forEach(element => {
                 const nameText = this.transpileIdentifier(element.name);
                 if (element.propertyName) {
                     const propertyText = this.transpileIdentifier(element.propertyName);
@@ -335,7 +347,7 @@ export abstract class LuaTranspiler {
             return result;
         } else if (ts.isNamespaceImport(imports)) {
             const resolvedImportPath = this.getImportPath(importPathWithoutQuotes);
-            return `local ${this.transpileIdentifier(imports.name)} = require(${resolvedImportPath})\n`;
+            return `local ${this.transpileIdentifier(imports.name)} = ${requireKeyword}(${resolvedImportPath})\n`;
         } else {
             throw TSTLErrors.UnsupportedImportType(imports);
         }
@@ -786,7 +798,9 @@ export abstract class LuaTranspiler {
             case ts.SyntaxKind.TypeOfExpression:
                 return this.transpileTypeOfExpression(node as ts.TypeOfExpression);
             case ts.SyntaxKind.EmptyStatement:
-                    return "";
+                return "";
+            case ts.SyntaxKind.SpreadElement:
+                return this.transpileSpreadElement(node as ts.SpreadElement);
             default:
                 throw TSTLErrors.UnsupportedKind("expression", node.kind, node);
         }
@@ -1029,6 +1043,10 @@ export abstract class LuaTranspiler {
 
         this.checkForLuaLibType(type);
 
+        if (classDecorators.has(DecoratorKind.Extension) || classDecorators.has(DecoratorKind.MetaExtension)) {
+            throw TSTLErrors.InvalidNewExpressionOnExtension(node);
+        }
+
         if (classDecorators.has(DecoratorKind.CustomConstructor)) {
             const customDecorator = classDecorators.get(DecoratorKind.CustomConstructor);
             if (!customDecorator.args[0]) {
@@ -1186,6 +1204,8 @@ export abstract class LuaTranspiler {
         const caller = this.transpileExpression(expression.expression);
         const expressionName = this.transpileIdentifier(expression.name);
         switch (expressionName) {
+            case "concat":
+                return this.transpileLuaLibFunction(LuaLibFeature.ArrayConcat, caller, params);
             case "push":
                 return this.transpileLuaLibFunction(LuaLibFeature.ArrayPush, caller, params);
             case "pop":
@@ -1236,6 +1256,10 @@ export abstract class LuaTranspiler {
     public transpilePropertyAccessExpression(node: ts.PropertyAccessExpression): string {
         const property = node.name.text;
 
+        if (tsHelper.hasGetAccessor(node, this.checker)) {
+            return this.transpileGetAccessor(node);
+        }
+
         // Check for primitive types to override
         const type = this.checker.getTypeAtLocation(node.expression);
         switch (type.flags) {
@@ -1245,8 +1269,6 @@ export abstract class LuaTranspiler {
             case ts.TypeFlags.Object:
                 if (tsHelper.isArrayType(type, this.checker)) {
                     return this.transpileArrayProperty(node);
-                } else if (tsHelper.hasGetAccessor(node, this.checker)) {
-                    return this.transpileGetAccessor(node);
                 }
         }
 
@@ -1366,6 +1388,10 @@ export abstract class LuaTranspiler {
         return escapedText;
     }
 
+    public transpileSpreadElement(node: ts.SpreadElement): string {
+       return "unpack(" + this.transpileExpression(node.expression) + ")";
+    }
+
     public transpileArrayBindingElement(name: ts.ArrayBindingElement): string {
         if (ts.isOmittedExpression(name)) {
             return "__";
@@ -1566,13 +1592,6 @@ export abstract class LuaTranspiler {
 
         let result = "";
 
-        if (!isExtension && !isMetaExtension) {
-            result += this.transpileClassCreationMethods(node, instanceFields, extendsType);
-        } else {
-            // export empty table
-            this.pushExport(className, node, true);
-        }
-
         // Overwrite the original className with the class we are overriding for extensions
         if (isMetaExtension) {
             if (!extendsType) {
@@ -1592,6 +1611,20 @@ export abstract class LuaTranspiler {
             }
         }
 
+        if (!isExtension && !isMetaExtension) {
+            result += this.transpileClassCreationMethods(node, instanceFields, extendsType);
+        } else {
+            for (const f of instanceFields) {
+                // Get identifier
+                const fieldIdentifier = f.name as ts.Identifier;
+                const fieldName = this.transpileIdentifier(fieldIdentifier);
+
+                const value = this.transpileExpression(f.initializer);
+
+                result += this.indent + `${className}.${fieldName} = ${value}\n`;
+            }
+        }
+
         // Add static declarations
         for (const field of staticFields) {
             const fieldName = this.transpileIdentifier(field.name as ts.Identifier);
diff --git a/src/lualib/ArrayConcat.ts b/src/lualib/ArrayConcat.ts
new file mode 100644
index 000000000..06d5206b3
--- /dev/null
+++ b/src/lualib/ArrayConcat.ts
@@ -0,0 +1,22 @@
+declare function pcall(func: () => any): any;
+declare function type(val: any): string;
+
+function __TS__ArrayConcat(arr1: any[], ...args: any[]): any[] {
+  const out: any[] = [];
+  for (const val of arr1) {
+    out[out.length] = val;
+  }
+  for (const arg of args) {
+    // Hack because we don't have an isArray function
+    if (pcall(() => (arg as any[]).length) && type(arg) !== "string") {
+        const argAsArray = (arg as any[]);
+        for (const val of argAsArray) {
+            out[out.length] = val;
+        }
+    } else {
+        out[out.length] = arg;
+    }
+  }
+
+  return out;
+}
diff --git a/src/targets/Transpiler.52.ts b/src/targets/Transpiler.52.ts
index 196f63a2a..31a6f4dcb 100644
--- a/src/targets/Transpiler.52.ts
+++ b/src/targets/Transpiler.52.ts
@@ -63,4 +63,9 @@ export class LuaTranspiler52 extends LuaTranspiler51 {
     public transpileDestructingAssignmentValue(node: ts.Expression): string {
         return `table.unpack(${this.transpileExpression(node)})`;
     }
+
+    /** @override */
+    public transpileSpreadElement(node: ts.SpreadElement): string {
+      return "table.unpack(" + this.transpileExpression(node.expression) + ")";
+    }
 }
diff --git a/test/translation/lua/classExtension4.lua b/test/translation/lua/classExtension4.lua
new file mode 100644
index 000000000..2d0c01b99
--- /dev/null
+++ b/test/translation/lua/classExtension4.lua
@@ -0,0 +1,4 @@
+MyClass.test = "test"
+MyClass.testP = "testP"
+function MyClass.myFunction(self)
+end
\ No newline at end of file
diff --git a/test/translation/ts/classExtension1.ts b/test/translation/ts/classExtension1.ts
index 922185c25..cf293483d 100644
--- a/test/translation/ts/classExtension1.ts
+++ b/test/translation/ts/classExtension1.ts
@@ -1,4 +1,4 @@
 /** !Extension */
 class MyClass {
-    myFunction() {}
-}
\ No newline at end of file
+    public myFunction() {}
+}
diff --git a/test/translation/ts/classExtension2.ts b/test/translation/ts/classExtension2.ts
index 1b9d54732..109160d97 100644
--- a/test/translation/ts/classExtension2.ts
+++ b/test/translation/ts/classExtension2.ts
@@ -4,5 +4,5 @@ class TestClass {
 
 /** !Extension */
 class MyClass extends TestClass {
-    myFunction() {}
+    public myFunction() {}
 }
diff --git a/test/translation/ts/classExtension3.ts b/test/translation/ts/classExtension3.ts
index a31129841..287c46d3f 100644
--- a/test/translation/ts/classExtension3.ts
+++ b/test/translation/ts/classExtension3.ts
@@ -1,9 +1,9 @@
 /** !Extension RenamedTestClass */
 class TestClass {
-    myFunction() {}
+    public myFunction() {}
 }
 
 /** !Extension RenamedMyClass */
 class MyClass extends TestClass {
-    myFunction() {}
+    public myFunction() {}
 }
diff --git a/test/translation/ts/classExtension4.ts b/test/translation/ts/classExtension4.ts
new file mode 100644
index 000000000..2183c5610
--- /dev/null
+++ b/test/translation/ts/classExtension4.ts
@@ -0,0 +1,6 @@
+/** !Extension */
+class MyClass {
+    public test: string = "test";
+    private testP: string = "testP";
+    public myFunction() {}
+}
diff --git a/test/unit/decoratorMetaExtension.spec.ts b/test/unit/decoratorMetaExtension.spec.ts
index c8b5694e9..d29f51467 100644
--- a/test/unit/decoratorMetaExtension.spec.ts
+++ b/test/unit/decoratorMetaExtension.spec.ts
@@ -1,4 +1,4 @@
-import { Expect, Test, TestCase } from "alsatian";
+import { Expect, Test } from "alsatian";
 import * as util from "../src/util";
 
 import { TranspileError } from "../../src/Errors";
@@ -44,4 +44,20 @@ export class DecoratorMetaExtension {
         }).toThrowError(TranspileError,
                         "!MetaExtension requires the extension of the metatable class.");
     }
+
+    @Test("DontAllowInstantiation")
+    public dontAllowInstantiation(): void {
+        Expect(() => {
+            util.transpileString(
+                `
+                declare class _LOADED;
+                /** !MetaExtension */
+                class Ext extends _LOADED {
+                }
+                const e = new Ext();
+                `
+            );
+        }).toThrowError(TranspileError,
+                        "Cannot construct classes with decorator '!Extension' or '!MetaExtension'.");
+    }
 }
diff --git a/test/unit/expressions.spec.ts b/test/unit/expressions.spec.ts
index 69bef8ab1..9a746027c 100644
--- a/test/unit/expressions.spec.ts
+++ b/test/unit/expressions.spec.ts
@@ -322,7 +322,7 @@ export class ExpressionTests {
         const identifier = ts.createIdentifier("fromCodePoint");
         Expect(() => transpiler.transpileStringExpression(identifier))
             .toThrowError(TranspileError, "string property fromCodePoint is/are not supported " +
-                          "for target Lua JIT.");
+                          "for target Lua jit.");
     }
 
     @Test("Unknown string expression error")
@@ -331,7 +331,7 @@ export class ExpressionTests {
 
         const identifier = ts.createIdentifier("abcd");
         Expect(() => transpiler.transpileStringExpression(identifier))
-            .toThrowError(TranspileError, "string property abcd is/are not supported for target Lua JIT.");
+            .toThrowError(TranspileError, "string property abcd is/are not supported for target Lua jit.");
     }
 
     @Test("Unsupported array function error")
diff --git a/test/unit/lualib/lualib.spec.ts b/test/unit/lualib/lualib.spec.ts
index 30279827c..328e346ee 100644
--- a/test/unit/lualib/lualib.spec.ts
+++ b/test/unit/lualib/lualib.spec.ts
@@ -172,6 +172,33 @@ export class LuaLibArrayTests {
         }
     }
 
+    @TestCase([], [])
+    @TestCase([1, 2, 3], [])
+    @TestCase([1, 2, 3], [4])
+    @TestCase([1, 2, 3], [4, 5])
+    @TestCase([1, 2, 3], [4, 5])
+    @TestCase([1, 2, 3], 4, [5])
+    @TestCase([1, 2, 3], 4, [5, 6])
+    @TestCase([1, 2, 3], 4, [5, 6], 7)
+    @TestCase([1, 2, 3], "test", [5, 6], 7, ["test1", "test2"])
+    @TestCase([1, 2, "test"], "test", ["test1", "test2"])
+    @Test("array.concat")
+    public concat<T>(arr: T[], ...args: T[]) {
+        const argStr = args.map(arg => JSON.stringify(arg)).join(",");
+        // Transpile
+        const lua = util.transpileString(
+            `let concatTestTable = ${JSON.stringify(arr)};
+            return JSONStringify(concatTestTable.concat(${argStr}));`
+        );
+
+        // Execute
+        const result = util.executeLua(lua);
+
+        // Assert
+        const concatArr = arr.concat(...args);
+        Expect(result).toBe(JSON.stringify(concatArr));
+    }
+
     @TestCase([], "")
     @TestCase(["test1"], "test1")
     @TestCase(["test1", "test2"], "test1,test2")
@@ -308,7 +335,7 @@ export class LuaLibArrayTests {
         // Assert
         Expect(result).toBe(expected);
     }
-   
+
     @TestCase("true", 11)
     @TestCase("false", 13)
     @TestCase("a < 4", 13)
diff --git a/test/unit/spreadElement.spec.ts b/test/unit/spreadElement.spec.ts
new file mode 100644
index 000000000..50bf8f2dc
--- /dev/null
+++ b/test/unit/spreadElement.spec.ts
@@ -0,0 +1,24 @@
+import { Expect, Test, TestCase } from "alsatian";
+
+import { LuaTarget } from "../../src/Transpiler";
+import * as util from "../src/util";
+
+export class SpreadElementTest {
+
+    @TestCase([])
+    @TestCase([1, 2, 3])
+    @TestCase([1, "test", 3])
+    @Test("Spread Element Push")
+    public spreadElementPush(inp: any[]) {
+        const lua = util.transpileString(`return JSONStringify([].push(...${JSON.stringify(inp)}));`);
+        const result = util.executeLua(lua);
+        Expect(result).toBe([].push(...inp));
+    }
+
+    @Test("Spread Element Lua 5.1")
+    public spreadElement51() {
+        // Cant test functional because our VM doesn't run on 5.1
+        const lua = util.transpileString(`[].push(...${JSON.stringify([1, 2, 3])});`, {luaTarget: LuaTarget.Lua51});
+        Expect(lua).toBe("__TS__ArrayPush({}, unpack({1,2,3}));");
+    }
+}
diff --git a/tslint.json b/tslint.json
index bb6058aba..d4505f068 100644
--- a/tslint.json
+++ b/tslint.json
@@ -31,9 +31,9 @@
         "interface-name": false,
         "radix": false,
         "typedef": [
-          true,
-          "call-signature",
-          "property-declaration"
+            true,
+            "call-signature",
+            "property-declaration"
         ]
     },
     "rulesDirectory": []