diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/ast/ASTType.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/ast/ASTType.java
index b398ca9a73..bdd26c4f59 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/ast/ASTType.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/ast/ASTType.java
@@ -23,11 +23,11 @@ public class ASTType extends AbstractJavaTypeNode {
     }
 
     public String getTypeImage() {
-        ASTPrimitiveType prim = getFirstDescendantOfType(ASTPrimitiveType.class);
-        if (prim != null) {
-            return prim.getImage();
+        ASTClassOrInterfaceType refType = getFirstDescendantOfType(ASTClassOrInterfaceType.class);
+        if (refType != null) {
+            return refType.getImage();
         }
-        return getFirstDescendantOfType(ASTClassOrInterfaceType.class).getImage();
+        return getFirstDescendantOfType(ASTPrimitiveType.class).getImage();
     }
 
     public int getArrayDepth() {
diff --git a/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/unusedcode/xml/UnusedPrivateMethod.xml b/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/unusedcode/xml/UnusedPrivateMethod.xml
index 1b66422495..b5d810c04b 100644
--- a/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/unusedcode/xml/UnusedPrivateMethod.xml
+++ b/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/unusedcode/xml/UnusedPrivateMethod.xml
@@ -1531,4 +1531,22 @@ public class Something {
 }
 ]]></code>
     </test-code>
+
+    <test-code>
+        <description>#521 UnusedPrivateMethod returns false positives with primitive data type in map argument</description>
+        <expected-problems>0</expected-problems>
+        <code><![CDATA[
+        public class Foo {
+          public Foo() {
+            Map<String, double[]> map = new LinkedHashMap<>();
+            addToMap(map);
+          }
+
+          private void addToMap(Map<String, double[]> map) {
+            map.put("foo", new double[]{0., 1.});
+          }
+        }
+        ]]></code>
+    </test-code>
+
 </test-data>
diff --git a/src/site/markdown/overview/changelog.md b/src/site/markdown/overview/changelog.md
index 26d98f53d7..3b8c976417 100644
--- a/src/site/markdown/overview/changelog.md
+++ b/src/site/markdown/overview/changelog.md
@@ -13,6 +13,7 @@ This is a major release.
     *   [Java Type Resolution](#Java_Type_Resolution)
     *   [Metrics Framework](#Metrics_Framework)
     *   [Configuration Error Reporting](#Configuration_Error_Reporting)
+    *   [Java Symbol Table](#Java_Symbol_Table)
     *   [Modified Rules](#Modified_Rules)
     *   [Removed Rules](#Removed_Rules)
 * [Fixed Issues](#Fixed_Issues)
@@ -79,6 +80,13 @@ and include them to such reports.
 *   The deprecated rule `UseSingleton` has been removed from the ruleset `java-design`. The rule has been renamed
     long time ago to `UseUtilityClass`.
 
+
+#### Java Symbol Table
+
+*   A [bug in symbol table](https://github.com/pmd/pmd/pull/549/commits/0958621ca884a8002012fc7738308c8dfc24b97c) prevented
+    the symbol table analysis to properly match primitive arrays types. The issue [affected the `java-unsedcode/UnusedPrivateMethod`](https://github.com/pmd/pmd/issues/521)
+    rule, but other rules may now produce improved results as consequence of this fix.
+
 ### Fixed Issues
 
 *   apex
@@ -95,6 +103,8 @@ and include them to such reports.
     *   [#408](https://github.com/pmd/pmd/issues/408): \[java] DFA not analyzing asserts
 *   java-sunsecure
     *   [#468](https://github.com/pmd/pmd/issues/468): \[java] ArrayIsStoredDirectly false positive
+*   java-unusedcode
+    *   [#521](https://github.com/pmd/pmd/issues/521): \[java] UnusedPrivateMethod returns false positives with primitive data type in map argument
 *   java-unnecessarycode
     *   [#412](https://github.com/pmd/pmd/issues/412): \[java] java-unnecessarycode/UnnecessaryFinalModifier missing cases