diff --git a/sootup.callgraph/src/main/java/sootup/callgraph/AbstractCallGraphAlgorithm.java b/sootup.callgraph/src/main/java/sootup/callgraph/AbstractCallGraphAlgorithm.java
index 7ab1607c983..b07da6e1747 100644
--- a/sootup.callgraph/src/main/java/sootup/callgraph/AbstractCallGraphAlgorithm.java
+++ b/sootup.callgraph/src/main/java/sootup/callgraph/AbstractCallGraphAlgorithm.java
@@ -313,16 +313,21 @@ protected abstract void postProcessingMethod(
   @Nonnull
   @Override
   public CallGraph addClass(@Nonnull CallGraph oldCallGraph, @Nonnull JavaClassType classType) {
-    MutableCallGraph updated = oldCallGraph.copy();
-
     SootClass<?> clazz = view.getClassOrThrow(classType);
     Set<MethodSignature> newMethodSignatures =
-        clazz.getMethods().stream().map(Method::getSignature).collect(Collectors.toSet());
+        clazz.getMethods().stream()
+            .map(Method::getSignature)
+            .filter(methodSig -> !oldCallGraph.containsMethod(methodSig))
+            .collect(Collectors.toSet());
 
-    if (newMethodSignatures.stream().anyMatch(oldCallGraph::containsMethod)) {
-      throw new IllegalArgumentException("CallGraph already contains methods from " + classType);
+    // were all the added method signatures already visited in the CallGraph? i.e. is there
+    // something to add?
+    if (newMethodSignatures.isEmpty()) {
+      return oldCallGraph;
     }
 
+    MutableCallGraph updated = oldCallGraph.copy();
+
     // Step 1: Add edges from the new methods to other methods
     Deque<MethodSignature> workList = new ArrayDeque<>(newMethodSignatures);
     Set<MethodSignature> processed = new HashSet<>(oldCallGraph.getMethodSignatures());
@@ -354,8 +359,10 @@ public CallGraph addClass(@Nonnull CallGraph oldCallGraph, @Nonnull JavaClassTyp
               MethodSignature overridingMethodSig =
                   clazz.getMethod(overriddenMethodSig.getSubSignature()).get().getSignature();
 
-              for (MethodSignature callingMethodSig : updated.callsTo(overriddenMethodSig)) {
-                updated.addCall(callingMethodSig, overridingMethodSig);
+              if (updated.containsMethod(overriddenMethodSig)) {
+                for (MethodSignature callingMethodSig : updated.callsTo(overriddenMethodSig)) {
+                  updated.addCall(callingMethodSig, overridingMethodSig);
+                }
               }
             });
 
diff --git a/sootup.java.core/src/main/java/sootup/java/core/JavaSootClass.java b/sootup.java.core/src/main/java/sootup/java/core/JavaSootClass.java
index c4ed4b40049..a4962269df4 100644
--- a/sootup.java.core/src/main/java/sootup/java/core/JavaSootClass.java
+++ b/sootup.java.core/src/main/java/sootup/java/core/JavaSootClass.java
@@ -37,6 +37,7 @@
 import sootup.core.signatures.MethodSubSignature;
 import sootup.core.types.ClassType;
 import sootup.core.types.Type;
+import sootup.java.core.types.JavaClassType;
 import sootup.java.core.views.JavaView;
 
 public class JavaSootClass extends SootClass<JavaSootClassSource> {
@@ -45,6 +46,12 @@ public JavaSootClass(JavaSootClassSource classSource, SourceType sourceType) {
     super(classSource, sourceType);
   }
 
+  @Nonnull
+  @Override
+  public JavaClassType getType() {
+    return (JavaClassType) super.getType();
+  }
+
   /**
    * Get all annotations on this class. If provided with a View, will also resolve all inherited
    * annotations from super classes.