diff --git a/apisupport/apisupport.ant/src/org/netbeans/modules/apisupport/project/ui/customizer/CustomizerSources.form b/apisupport/apisupport.ant/src/org/netbeans/modules/apisupport/project/ui/customizer/CustomizerSources.form
index 9b64d244fd61..a61bf2dd0f19 100644
--- a/apisupport/apisupport.ant/src/org/netbeans/modules/apisupport/project/ui/customizer/CustomizerSources.form
+++ b/apisupport/apisupport.ant/src/org/netbeans/modules/apisupport/project/ui/customizer/CustomizerSources.form
@@ -72,6 +72,9 @@
           <Connection code="&quot;mmm&quot;" type="code"/>
         </Property>
       </Properties>
+      <AuxValues>
+        <AuxValue name="JavaCodeGenerator_TypeParameters" type="java.lang.String" value="&lt;String&gt;"/>
+      </AuxValues>
       <Constraints>
         <Constraint layoutClass="org.netbeans.modules.form.compat2.layouts.DesignGridBagLayout" value="org.netbeans.modules.form.compat2.layouts.DesignGridBagLayout$GridBagConstraintsDescription">
           <GridBagConstraints gridX="1" gridY="2" gridWidth="1" gridHeight="1" fill="0" ipadX="0" ipadY="0" insetsTop="18" insetsLeft="0" insetsBottom="0" insetsRight="0" anchor="17" weightX="0.0" weightY="0.0"/>
diff --git a/apisupport/apisupport.ant/src/org/netbeans/modules/apisupport/project/ui/customizer/CustomizerSources.java b/apisupport/apisupport.ant/src/org/netbeans/modules/apisupport/project/ui/customizer/CustomizerSources.java
index 5eee85a0c127..4e92148bf3fc 100644
--- a/apisupport/apisupport.ant/src/org/netbeans/modules/apisupport/project/ui/customizer/CustomizerSources.java
+++ b/apisupport/apisupport.ant/src/org/netbeans/modules/apisupport/project/ui/customizer/CustomizerSources.java
@@ -54,7 +54,7 @@ public void actionPerformed(ActionEvent e) {
                 if (srcLevelValueBeingUpdated) {
                     return;
                 }
-                final String oldLevel = getProperty(getJavacLanguageLevelKey());
+                final String oldLevel = getEffectiveJavacTarget();
                 final String newLevel = (String) srcLevelValue.getSelectedItem();
                 SpecificationVersion jdk5 = new SpecificationVersion("1.5"); // NOI18N
                 if (new SpecificationVersion(oldLevel).compareTo(jdk5) < 0 && new SpecificationVersion(newLevel).compareTo(jdk5) >= 0) {
@@ -99,7 +99,7 @@ protected void refresh() {
             for (String level : levels) {
                 srcLevelValue.addItem(level);
             }
-            srcLevelValue.setSelectedItem(getProperty(getJavacLanguageLevelKey()));
+            srcLevelValue.setSelectedItem(getEffectiveJavacTarget());
         } finally {
             srcLevelValueBeingUpdated = false;
         }
@@ -108,25 +108,43 @@ protected void refresh() {
     
     @Override
     public void store() {
-        setProperty(getJavacLanguageLevelKey(), (String) srcLevelValue.getSelectedItem());
+        String selected = (String) srcLevelValue.getSelectedItem();
+        if (!selected.equals(getEffectiveJavacTarget())) {
+            setProperty(getJavacLanguageLevelKey(), selected);
+        }
     }
 
     private String getJavacLanguageLevelKey() {
         return containsProperty(JAVAC_RELEASE) ? JAVAC_RELEASE : JAVAC_SOURCE;
     }
-    
+
+    private String getEffectiveJavacTarget() {
+        String release = props.getEvaluator().getProperty(JAVAC_RELEASE);
+        return isInteger(release) ? release : props.getEvaluator().getProperty(JAVAC_SOURCE);
+    }
+
+    @SuppressWarnings("UnnecessaryTemporaryOnConversionFromString")
+    private static boolean isInteger(String release) {
+        try {
+            Integer.parseInt(release);
+            return true;
+        } catch (IllegalArgumentException ex) {
+            return false;
+        }
+    }
+
     /** This method is called from within the constructor to
      * initialize the form.
      * WARNING: Do NOT modify this code. The content of this method is
      * always regenerated by the Form Editor.
      */
-    // <editor-fold defaultstate="collapsed" desc=" Generated Code ">//GEN-BEGIN:initComponents
+    // <editor-fold defaultstate="collapsed" desc="Generated Code">//GEN-BEGIN:initComponents
     private void initComponents() {
         java.awt.GridBagConstraints gridBagConstraints;
 
         prjFolder = new javax.swing.JLabel();
         srcLevel = new javax.swing.JLabel();
-        srcLevelValue = new javax.swing.JComboBox();
+        srcLevelValue = new javax.swing.JComboBox<>();
         filler = new javax.swing.JLabel();
         prjFolderValue = new javax.swing.JTextField();
         moduleSuite = new javax.swing.JLabel();
@@ -193,9 +211,7 @@ private void initComponents() {
         gridBagConstraints.weightx = 1.0;
         gridBagConstraints.insets = new java.awt.Insets(6, 0, 0, 0);
         add(moduleSuiteValue, gridBagConstraints);
-
-    }
-    // </editor-fold>//GEN-END:initComponents
+    }// </editor-fold>//GEN-END:initComponents
     
     // Variables declaration - do not modify//GEN-BEGIN:variables
     private javax.swing.JLabel filler;
@@ -204,7 +220,7 @@ private void initComponents() {
     private javax.swing.JLabel prjFolder;
     private javax.swing.JTextField prjFolderValue;
     private javax.swing.JLabel srcLevel;
-    private javax.swing.JComboBox srcLevelValue;
+    private javax.swing.JComboBox<String> srcLevelValue;
     // End of variables declaration//GEN-END:variables
     
     private static String getMessage(String key) {
@@ -233,7 +249,7 @@ private String[] sourceLevels(JavaPlatform platform) {
         } catch (Exception ex) {
             Exceptions.printStackTrace(ex);
         }
-        return levels.toArray(new String[0]);
+        return levels.toArray(String[]::new);
     }
 
 }