diff --git a/core/src/main/java/org/teavm/dependency/DefaultCallSite.java b/core/src/main/java/org/teavm/dependency/DefaultCallSite.java
index e82381ccc..3e7fdbcd9 100644
--- a/core/src/main/java/org/teavm/dependency/DefaultCallSite.java
+++ b/core/src/main/java/org/teavm/dependency/DefaultCallSite.java
@@ -80,7 +80,7 @@ public class DefaultCallSite implements CallSite, Serializable {
 
     @Override
     public Collection<? extends DefaultCallGraphNode> getCalledMethods() {
-        if (singleCalledMethod == null) {
+        if (singleCalledMethod != null) {
             return Collections.singletonList(singleCalledMethod);
         }
         if (readonlyCalledMethods == null) {
diff --git a/core/src/main/java/org/teavm/dependency/SerializableCallGraph.java b/core/src/main/java/org/teavm/dependency/SerializableCallGraph.java
index 558105af8..8e50575b1 100644
--- a/core/src/main/java/org/teavm/dependency/SerializableCallGraph.java
+++ b/core/src/main/java/org/teavm/dependency/SerializableCallGraph.java
@@ -49,7 +49,7 @@ class SerializableCallGraph implements Serializable {
         FieldReference field;
     }
 
-    static class Location {
+    static class Location implements Serializable {
         TextLocation value;
         int caller;
     }