diff --git a/src/main/java/io/github/classgraph/ClassInfo.java b/src/main/java/io/github/classgraph/ClassInfo.java
index 271c5aa7c..bd71f11bc 100644
--- a/src/main/java/io/github/classgraph/ClassInfo.java
+++ b/src/main/java/io/github/classgraph/ClassInfo.java
@@ -1685,9 +1685,6 @@ public ClassInfoList getInterfaces() {
      *         interface, otherwise returns the empty list.
      */
     public ClassInfoList getClassesImplementing() {
-        if (!isInterface()) {
-            throw new IllegalArgumentException("Class is not an interface: " + getName());
-        }
         // Subclasses of implementing classes also implement the interface
         final ReachableAndDirectlyRelatedClasses implementingClasses = this
                 .filterClassInfo(RelType.CLASSES_IMPLEMENTING, /* strictAccept = */ !isExternalClass);
@@ -1917,9 +1914,6 @@ public ClassInfoList getClassesWithAnnotation() {
         if (!scanResult.scanSpec.enableAnnotationInfo) {
             throw new IllegalArgumentException("Please call ClassGraph#enableAnnotationInfo() before #scan()");
         }
-        if (!isAnnotation()) {
-            throw new IllegalArgumentException("Class is not an annotation: " + getName());
-        }
 
         // Get classes that have this annotation
         final ReachableAndDirectlyRelatedClasses classesWithAnnotation = this