diff --git a/java/java.completion/src/org/netbeans/modules/java/completion/JavaCompletionTask.java b/java/java.completion/src/org/netbeans/modules/java/completion/JavaCompletionTask.java
index 7cf25ed54e07..e77e03eae5bd 100644
--- a/java/java.completion/src/org/netbeans/modules/java/completion/JavaCompletionTask.java
+++ b/java/java.completion/src/org/netbeans/modules/java/completion/JavaCompletionTask.java
@@ -2218,6 +2218,9 @@ private void insideNewClass(Env env) throws IOException {
                 case GTGTGT:
                     controller = env.getController();
                     TypeMirror tm = controller.getTrees().getTypeMirror(new TreePath(path, nc.getIdentifier()));
+                    if (tm.getKind() == TypeKind.ERROR) {
+                        tm = env.getController().getTrees().getOriginalType((ErrorType) tm);
+                    }
                     addMembers(env, tm, ((DeclaredType) tm).asElement(), EnumSet.of(CONSTRUCTOR), null, false, false, false, true, addSwitchItemDefault);
                     break;
             }
diff --git a/java/java.completion/test/unit/data/goldenfiles/org/netbeans/modules/java/completion/JavaCompletionTaskTest/1.8/diamond1.pass b/java/java.completion/test/unit/data/goldenfiles/org/netbeans/modules/java/completion/JavaCompletionTaskTest/1.8/diamond1.pass
new file mode 100644
index 000000000000..488d6ffd6f56
--- /dev/null
+++ b/java/java.completion/test/unit/data/goldenfiles/org/netbeans/modules/java/completion/JavaCompletionTaskTest/1.8/diamond1.pass
@@ -0,0 +1,2 @@
+public Test(T value)
+public Test(String name, T value)
diff --git a/java/java.completion/test/unit/src/org/netbeans/modules/java/completion/JavaCompletionTask18FeaturesTest.java b/java/java.completion/test/unit/src/org/netbeans/modules/java/completion/JavaCompletionTask18FeaturesTest.java
index d36656a73820..0f3077788a61 100644
--- a/java/java.completion/test/unit/src/org/netbeans/modules/java/completion/JavaCompletionTask18FeaturesTest.java
+++ b/java/java.completion/test/unit/src/org/netbeans/modules/java/completion/JavaCompletionTask18FeaturesTest.java
@@ -346,6 +346,21 @@ public void testEffectivellyFinal() throws Exception {
         performTest("Final", 1125, "var", "effectivellyFinal.pass", "1.8");
     }
 
+    public void testDiamond1() throws Exception {
+        performTest("Empty", 808,
+                """
+                package test;
+                public class Test {
+                    public static class Test<T> {
+                        public Test(T value) { }
+                        public Test(String name, T value) { }
+                    }
+                    private static void test() {
+                        new Test<>
+                """,
+                "diamond1.pass", "1.8");
+    }
+
     static {
         JavacParser.DISABLE_SOURCE_LEVEL_DOWNGRADE = true;
     }