diff --git a/duchain/builders/declarationbuilder.cpp b/duchain/builders/declarationbuilder.cpp
--- a/duchain/builders/declarationbuilder.cpp
+++ b/duchain/builders/declarationbuilder.cpp
@@ -937,6 +937,51 @@
     if ( identifier == thisQId
             && currentContext()->parentContext()
             && currentContext()->parentContext()->type() == DUContext::Class ) {
+        
+        // checks if imports \ArrayAccess
+        ClassDeclaration* currentClass = dynamic_cast<ClassDeclaration*>(currentContext()->parentContext()->owner());
+        ClassDeclaration* arrayAccess = nullptr;
+    
+        auto imports = currentContext()->parentContext()->importedParentContexts();
+        for( const DUContext::Import& ctx : imports ) {
+            DUContext* import = ctx.context(topContext());
+            if(import->type() == DUContext::Class) {
+                ClassDeclaration* importedClass = dynamic_cast<ClassDeclaration*>(import->owner());
+                if(importedClass) {
+                    if(importedClass->prettyName().str() == "ArrayAccess" && importedClass->classType() == ClassDeclarationData::ClassType::Interface && !import->parentContext()->owner()) {
+                        arrayAccess = importedClass;
+                    }
+                }
+            }
+        }
+        
+        IntegralType* thisVar = static_cast<IntegralType*>(type.data());
+        // check if this is used as array 
+        if(arrayAccess && currentClass && thisVar && thisVar->dataType() == AbstractType::TypeArray)
+        {
+            uint noOfFunc = 0;
+            auto declarations = currentContext()->parentContext()->localDeclarations();
+            // check if class implements all 4 functions
+            for(auto &dec : declarations) {
+                if(dec->isFunctionDeclaration()) {
+                    QualifiedIdentifier func = dec->qualifiedIdentifier();
+                    QString funcname = func.last().identifier().str();
+                    if(funcname == "offsetexists" || funcname == "offsetget" || funcname == "offsetset" || funcname == "offsetunset") {
+                        noOfFunc++;
+                    }
+                }
+            }
+            
+            if(noOfFunc < 4) {
+                // check if class is not abstract
+                if(currentClass->classModifier() != ClassDeclarationData::ClassModifier::Abstract) {
+                    reportError(i18n("Class %1 contains %2 abstract methods and must therefore be declared abstract or implement the remaining methods.",currentClass->prettyName().str(),4-noOfFunc), QList<AstNode*>() << node);
+                }
+            }
+            
+            return;
+        }
+        
         reportError(i18n("Cannot re-assign $this."), QList<AstNode*>() << node);
         return;
     }
diff --git a/duchain/tests/duchain.h b/duchain/tests/duchain.h
--- a/duchain/tests/duchain.h
+++ b/duchain/tests/duchain.h
@@ -149,6 +149,8 @@
     void bug296709();
     void declareFinalMethod();
     void testTodoExtractor();
+    void useThisAsArray();
+    void wrongUseOfThisAsArray();
 };
 
 }
diff --git a/duchain/tests/duchain.cpp b/duchain/tests/duchain.cpp
--- a/duchain/tests/duchain.cpp
+++ b/duchain/tests/duchain.cpp
@@ -2954,3 +2954,47 @@
     QCOMPARE(top->problems().at(1)->description(), QString("FIXME blub"));
     QCOMPARE(top->problems().at(1)->range(), RangeInRevision(2, 4, 2, 14));
 }
+
+void TestDUChain::useThisAsArray()
+{
+    QByteArray method("<?php\n"
+                      "  interface ArrayAccess{} "
+                      "  class A implements \\ArrayAccess\n"
+                      "  {\n"
+                      "      $values = [];\n"
+                      "      function offsetGet($offset) { return $this->values[$offset]; }\n"
+                      "      function offsetSet($offset, $value) { $this->values[$offset] = $value; }\n"
+                      "      function offsetExists($offset) { return array_key_exists($offset, $this->values); }\n"
+                      "      function offsetUnset($offset) { unset($this->values[$offset]); }\n"
+                      "      function setTest() { $this['test'] = 'test'; }  \n"
+                      "  }\n");
+    
+    TopDUContext* top = parse(method);
+    QVERIFY(top);
+    DUChainReleaser releaseTop(top);
+    DUChainWriteLocker lock(DUChain::lock());
+    
+    QCOMPARE(top->importedParentContexts().count(), 1);
+    QVERIFY(DUChain::self()->chainForDocument(internalFunctionFile()));
+    QCOMPARE(DUChain::self()->chainForDocument(internalFunctionFile()), top->importedParentContexts().first().context(top));
+    
+    QVERIFY(top->problems().isEmpty());
+}
+
+void TestDUChain::wrongUseOfThisAsArray()
+{
+    // missing functions from \ArrayAccess and not declared abstract
+    QByteArray method("<?php\n"
+                      "  interface ArrayAccess{} "
+                      "  class A implements \\ArrayAccess\n"
+                      "  {\n"
+                      "      public function setTest() { $this['test'] = 'test'; }  \n"
+                      "  }\n");
+
+    TopDUContext* top = parse(method);
+    QVERIFY(top);
+    DUChainReleaser releaseTop(top);
+    DUChainWriteLocker lock(DUChain::lock());
+    
+    QCOMPARE(top->problems().size(),1);
+}