diff --git a/tasty-query/shared/src/main/scala/tastyquery/reader/classfiles/ClassfileParser.scala b/tasty-query/shared/src/main/scala/tastyquery/reader/classfiles/ClassfileParser.scala
index 0967dae4..6260ef87 100644
--- a/tasty-query/shared/src/main/scala/tastyquery/reader/classfiles/ClassfileParser.scala
+++ b/tasty-query/shared/src/main/scala/tastyquery/reader/classfiles/ClassfileParser.scala
@@ -329,6 +329,18 @@ private[reader] object ClassfileParser {
       else if cls.isString then rctx.createStringMagicMethods(cls)
       else if cls.isJavaEnum then rctx.createEnumMagicMethods(cls)
 
+    // Synthesize a constructor for interfaces
+    if cls.isTrait then
+      val ctor = TermSymbol
+        .create(nme.Constructor, cls)
+        .withDeclaredType(cls.makePolyConstructorType(MethodType(Nil, Nil, rctx.UnitType)))
+        .withFlags(Method | JavaDefined, None)
+        .setAnnotations(Nil)
+        .autoFillParamSymss()
+      ctor.paramSymss.foreach(_.merge.foreach(_.setAnnotations(Nil)))
+      allRegisteredSymbols += ctor
+    end if
+
     loadMembers()
 
     val annotations = readAnnotations(cls, attributes)
diff --git a/test-sources/src/main/scala/simple_trees/ClassExtendsJavaInterface.scala b/test-sources/src/main/scala/simple_trees/ClassExtendsJavaInterface.scala
new file mode 100644
index 00000000..68c475fe
--- /dev/null
+++ b/test-sources/src/main/scala/simple_trees/ClassExtendsJavaInterface.scala
@@ -0,0 +1,3 @@
+package simple_trees
+
+class ClassExtendsJavaInterface extends javadefined.JavaInterface1()
diff --git a/test-sources/src/main/scala/simple_trees/ClassExtendsPolyJavaInterface.scala b/test-sources/src/main/scala/simple_trees/ClassExtendsPolyJavaInterface.scala
new file mode 100644
index 00000000..e9c2ca4a
--- /dev/null
+++ b/test-sources/src/main/scala/simple_trees/ClassExtendsPolyJavaInterface.scala
@@ -0,0 +1,5 @@
+package simple_trees
+
+class ClassExtendsPolyJavaInterface extends java.util.function.Predicate[String]():
+  def test(t: String): Boolean = t.isEmpty()
+end ClassExtendsPolyJavaInterface