diff --git a/src/main/antlr4/de/dhbwstuttgart/parser/antlr/Java17Parser.g4 b/src/main/antlr4/de/dhbwstuttgart/parser/antlr/Java17Parser.g4
index 70b78141..64275b2f 100644
--- a/src/main/antlr4/de/dhbwstuttgart/parser/antlr/Java17Parser.g4
+++ b/src/main/antlr4/de/dhbwstuttgart/parser/antlr/Java17Parser.g4
@@ -33,8 +33,8 @@ parser grammar Java17Parser;
 
 options { tokenVocab=Java17Lexer; }
 
-compilationUnit
-    : packageDeclaration? importDeclaration* typeDeclaration*
+sourceFile
+    : packageDeclaration? importDeclaration* classOrInterface*
     | moduleDeclaration EOF
     ;
 
@@ -46,7 +46,7 @@ importDeclaration
     : IMPORT STATIC? qualifiedName ('.' '*')? ';'
     ;
 
-typeDeclaration
+classOrInterface
     : classOrInterfaceModifier*
       (classDeclaration | enumDeclaration | interfaceDeclaration | annotationTypeDeclaration | recordDeclaration)
     | ';'
@@ -79,19 +79,19 @@ variableModifier
     ;
 
 classDeclaration
-    : CLASS identifier typeParameters?
+    : CLASS identifier genericDeclarationList?
       (EXTENDS typeType)?
       (IMPLEMENTS typeList)?
       (PERMITS typeList)? // Java17
       classBody
     ;
 
-typeParameters
-    : '<' typeParameter (',' typeParameter)* '>'
+genericDeclarationList
+    : '<' genericTypeVar (',' genericTypeVar)* '>'
     ;
 
-typeParameter
-    : annotation* identifier (EXTENDS annotation* typeBound)?
+genericTypeVar
+    : annotation* identifier ((EXTENDS | IMPLEMENTS) annotation* typeBound)?
     ;
 
 typeBound
@@ -115,7 +115,7 @@ enumBodyDeclarations
     ;
 
 interfaceDeclaration
-    : INTERFACE identifier typeParameters? (EXTENDS typeList)? (PERMITS typeList)? interfaceBody
+    : INTERFACE identifier genericDeclarationList? (EXTENDS typeList)? (PERMITS typeList)? interfaceBody
     ;
 
 classBody
@@ -133,16 +133,15 @@ classBodyDeclaration
     ;
 
 memberDeclaration
-    : recordDeclaration //Java17
-    | methodDeclaration
-    | genericMethodDeclaration
+    : classOrInterface
     | fieldDeclaration
-    | constructorDeclaration
-    | genericConstructorDeclaration
-    | interfaceDeclaration
-    | annotationTypeDeclaration
-    | classDeclaration
-    | enumDeclaration
+    | method
+    | constructor
+    ;
+
+method
+    : methodDeclaration
+    | genericMethodDeclaration
     ;
 
 /* We use rule this even for void methods which cannot have [] after parameters.
@@ -151,8 +150,8 @@ memberDeclaration
    for invalid return type after parsing.
  */
 methodDeclaration
-    : typeTypeOrVoid identifier formalParameters ('[' ']')*
-      (THROWS qualifiedNameList)?
+    : refType? identifier formalParameters ('[' ']')*
+      (THROWS exceptionList)?
       methodBody
     ;
 
@@ -161,25 +160,30 @@ methodBody
     | ';'
     ;
 
-typeTypeOrVoid
+refType
     : typeType
     | VOID
     ;
 
 genericMethodDeclaration
-    : typeParameters methodDeclaration
+    : genericDeclarationList methodDeclaration
+    ;
+
+constructor
+    : genericConstructorDeclaration
+    | constructorDeclaration
     ;
 
 genericConstructorDeclaration
-    : typeParameters constructorDeclaration
+    : genericDeclarationList constructorDeclaration
     ;
 
 constructorDeclaration
-    : identifier formalParameters (THROWS qualifiedNameList)? constructorBody=block
+    : identifier formalParameters (THROWS exceptionList)? constructorBody=block
     ;
 
 fieldDeclaration
-    : typeType variableDeclarators ';'
+    : typeType? variableDeclarators ';'
     ;
 
 interfaceBodyDeclaration
@@ -199,7 +203,7 @@ interfaceMemberDeclaration
     ;
 
 constDeclaration
-    : typeType constantDeclarator (',' constantDeclarator)* ';'
+    : typeType? constantDeclarator (',' constantDeclarator)* ';'
     ;
 
 constantDeclarator
@@ -225,11 +229,11 @@ interfaceMethodModifier
     ;
 
 genericInterfaceMethodDeclaration
-    : interfaceMethodModifier* typeParameters interfaceCommonBodyDeclaration
+    : interfaceMethodModifier* genericDeclarationList interfaceCommonBodyDeclaration
     ;
 
 interfaceCommonBodyDeclaration
-    : annotation* typeTypeOrVoid identifier formalParameters ('[' ']')* (THROWS qualifiedNameList)? methodBody
+    : annotation* refType? identifier formalParameters ('[' ']')* (THROWS exceptionList)? methodBody
     ;
 
 variableDeclarators
@@ -259,13 +263,29 @@ classOrInterfaceType
 
 typeArgument
     : typeType
-    | annotation* '?' ((EXTENDS | SUPER) typeType)?
+    | wildcardType
+    ;
+
+wildcardType
+    : annotation* '?' (extendsWildcardType | superWildcardType)?
+    ;
+
+extendsWildcardType
+    : EXTENDS typeType
+    ;
+
+superWildcardType
+    : SUPER typeType
     ;
 
 qualifiedNameList
     : qualifiedName (',' qualifiedName)*
     ;
 
+exceptionList
+    : qualifiedNameList
+    ;
+
 formalParameters
     : '(' ( receiverParameter?
           | receiverParameter (',' formalParameterList)?
@@ -274,7 +294,7 @@ formalParameters
     ;
 
 receiverParameter
-    : typeType (identifier '.')* THIS
+    : typeType? (identifier '.')* THIS
     ;
 
 formalParameterList
@@ -283,11 +303,11 @@ formalParameterList
     ;
 
 formalParameter
-    : variableModifier* typeType variableDeclaratorId
+    : variableModifier* typeType? variableDeclaratorId
     ;
 
 lastFormalParameter
-    : variableModifier* typeType annotation* '...' variableDeclaratorId
+    : variableModifier* typeType? annotation* '...' variableDeclaratorId
     ;
 
 // local variable type inference
@@ -417,7 +437,7 @@ requiresModifier
 // RECORDS - Java 17
 
 recordDeclaration
-    : RECORD identifier typeParameters? recordHeader
+    : RECORD identifier genericDeclarationList? recordHeader
       (IMPLEMENTS typeList)?
       recordBody
     ;
@@ -431,7 +451,7 @@ recordComponentList
     ;
 
 recordComponent
-    : typeType identifier
+    : typeType? identifier
     ;
 
 recordBody
@@ -451,7 +471,7 @@ blockStatement
     ;
 
 localVariableDeclaration
-    : variableModifier* (VAR identifier '=' expression | typeType variableDeclarators)
+    : variableModifier* (VAR identifier '=' expression | typeType? variableDeclarators)
     ;
 
 identifier
@@ -539,7 +559,7 @@ resources
     ;
 
 resource
-    : variableModifier* ( classOrInterfaceType variableDeclaratorId | VAR identifier ) '=' expression
+    : variableModifier* ( classOrInterfaceType? variableDeclaratorId | VAR identifier ) '=' expression
     | identifier
     ;
 
@@ -566,7 +586,7 @@ forInit
     ;
 
 enhancedForControl
-    : variableModifier* (typeType | VAR) variableDeclaratorId ':' expression
+    : variableModifier* (typeType? | VAR) variableDeclaratorId ':' expression
     ;
 
 // EXPRESSIONS
@@ -657,7 +677,7 @@ primary
     | SUPER
     | literal
     | identifier
-    | typeTypeOrVoid '.' CLASS
+    | refType '.' CLASS
     | nonWildcardTypeArguments (explicitGenericInvocationSuffix | THIS arguments)
     ;