diff --git a/docs/pages/release_notes.md b/docs/pages/release_notes.md
index 191d9f5e87..cc0ca22491 100644
--- a/docs/pages/release_notes.md
+++ b/docs/pages/release_notes.md
@@ -188,6 +188,7 @@ are deprecated as internal API.
 *   [#2730](https://github.com/pmd/pmd/pull/2730): Cleanup: StringBuilder issues - [XenoAmess](https://github.com/XenoAmess)
 *   [#2731](https://github.com/pmd/pmd/pull/2731): Cleanup: avoid compiling Patterns repeatedly - [XenoAmess](https://github.com/XenoAmess)
 *   [#2732](https://github.com/pmd/pmd/pull/2732): Cleanup: use StandardCharsets instead of Charset.forName - [XenoAmess](https://github.com/XenoAmess) 
+*   [#2733](https://github.com/pmd/pmd/pull/2733): Cleanup: Collection::addAll issues  - [XenoAmess](https://github.com/XenoAmess) 
 *   [#2734](https://github.com/pmd/pmd/pull/2734): Cleanup: use try with resources - [XenoAmess](https://github.com/XenoAmess)
 
 
diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/qname/ImmutableList.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/qname/ImmutableList.java
index 57335743c2..726dbceac9 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/qname/ImmutableList.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/qname/ImmutableList.java
@@ -563,11 +563,7 @@ interface ImmutableList<E> extends List<E> {
 
             @Override
             public List<E> toList() {
-                List<E> result = new ArrayList<>(size());
-                for (E item : this) {
-                    result.add(item);
-                }
-                return result;
+                return new ArrayList<>(this);
             }
 
 
diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/bestpractices/JUnitUseExpectedRule.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/bestpractices/JUnitUseExpectedRule.java
index e02b4069b2..c1fa59109d 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/bestpractices/JUnitUseExpectedRule.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/bestpractices/JUnitUseExpectedRule.java
@@ -58,8 +58,7 @@ public class JUnitUseExpectedRule extends AbstractJUnitRule {
             if (child instanceof ASTMethodDeclaration) {
                 boolean isJUnitMethod = isJUnitMethod((ASTMethodDeclaration) child, data);
                 if (inAnnotation || isJUnitMethod) {
-                    List<Node> found = new ArrayList<>();
-                    found.addAll((List<Node>) visit((ASTMethodDeclaration) child, data));
+                    List<Node> found = new ArrayList<>((List<Node>) visit((ASTMethodDeclaration) child, data));
                     for (Node name : found) {
                         addViolation(data, name);
                     }
diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/bestpractices/UnusedPrivateFieldRule.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/bestpractices/UnusedPrivateFieldRule.java
index 0fed0d1aa2..6cc74ef41f 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/bestpractices/UnusedPrivateFieldRule.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/bestpractices/UnusedPrivateFieldRule.java
@@ -32,8 +32,7 @@ public class UnusedPrivateFieldRule extends AbstractLombokAwareRule {
 
     @Override
     protected Collection<String> defaultSuppressionAnnotations() {
-        Collection<String> defaultValues = new ArrayList<>();
-        defaultValues.addAll(super.defaultSuppressionAnnotations());
+        Collection<String> defaultValues = new ArrayList<>(super.defaultSuppressionAnnotations());
         defaultValues.add("java.lang.Deprecated");
         defaultValues.add("javafx.fxml.FXML");
         defaultValues.add("lombok.experimental.Delegate");
diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/design/SingularFieldRule.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/design/SingularFieldRule.java
index 802edaa79b..ce1777ce48 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/design/SingularFieldRule.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/design/SingularFieldRule.java
@@ -61,8 +61,7 @@ public class SingularFieldRule extends AbstractLombokAwareRule {
 
     @Override
     protected Collection<String> defaultSuppressionAnnotations() {
-        Collection<String> defaultValues = new ArrayList<>();
-        defaultValues.addAll(super.defaultSuppressionAnnotations());
+        Collection<String> defaultValues = new ArrayList<>(super.defaultSuppressionAnnotations());
         defaultValues.add("lombok.experimental.Delegate");
         defaultValues.add("lombok.EqualsAndHashCode");
         return defaultValues;
diff --git a/pmd-java/src/test/java/net/sourceforge/pmd/typeresolution/testdata/MethodFirstPhase.java b/pmd-java/src/test/java/net/sourceforge/pmd/typeresolution/testdata/MethodFirstPhase.java
index 6073c907b7..f889b1a659 100644
--- a/pmd-java/src/test/java/net/sourceforge/pmd/typeresolution/testdata/MethodFirstPhase.java
+++ b/pmd-java/src/test/java/net/sourceforge/pmd/typeresolution/testdata/MethodFirstPhase.java
@@ -19,8 +19,7 @@ public class MethodFirstPhase {
 
         Exception b = vararg((Number) null);
 
-        Set<String> set = new HashSet<>();
-        set.addAll(Arrays.asList("a", "b")); // TODO: return type of method call Arrays.asList is missing
+        Set<String> set = new HashSet<>(Arrays.asList("a", "b")); // TODO: return type of method call Arrays.asList is missing
 
         List<String> myList = new ArrayList<>();
         Collections.sort(myList); // TODO: generic type variables on methods
diff --git a/pmd-jsp/src/test/java/net/sourceforge/pmd/lang/jsp/ast/JspDocStyleTest.java b/pmd-jsp/src/test/java/net/sourceforge/pmd/lang/jsp/ast/JspDocStyleTest.java
index 26a54a3f8b..52023dfe40 100644
--- a/pmd-jsp/src/test/java/net/sourceforge/pmd/lang/jsp/ast/JspDocStyleTest.java
+++ b/pmd-jsp/src/test/java/net/sourceforge/pmd/lang/jsp/ast/JspDocStyleTest.java
@@ -784,8 +784,7 @@ public class JspDocStyleTest extends AbstractJspNodesTst {
      * @return
      */
     private List<ASTElement> sortNodesByName(Collection<ASTElement> elements) {
-        List<ASTElement> list = new ArrayList<>();
-        list.addAll(elements);
+        List<ASTElement> list = new ArrayList<>(elements);
         Collections.sort(list, new Comparator<ASTElement>() {
             public int compare(ASTElement o1, ASTElement o2) {
                 if (o1.getName() == null) {
@@ -812,8 +811,7 @@ public class JspDocStyleTest extends AbstractJspNodesTst {
      * @return
      */
     private <T extends Node> List<T> sortByImage(Collection<T> elements) {
-        List<T> list = new ArrayList<>();
-        list.addAll(elements);
+        List<T> list = new ArrayList<>(elements);
         Collections.sort(list, new Comparator<Node>() {
             public int compare(Node o1, Node o2) {
                 if (o1.getImage() == null) {