diff --git a/.idea/runConfigurations/build_teavm_fast.xml b/.idea/runConfigurations/build_teavm_fast.xml
new file mode 100644
index 000000000..ecfe3b594
--- /dev/null
+++ b/.idea/runConfigurations/build_teavm_fast.xml
@@ -0,0 +1,28 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="build-teavm-fast" type="MavenRunConfiguration" factoryName="Maven">
+    <MavenSettings>
+      <option name="myGeneralSettings" />
+      <option name="myRunnerSettings" />
+      <option name="myRunnerParameters">
+        <MavenRunnerParameters>
+          <option name="profiles">
+            <set />
+          </option>
+          <option name="goals">
+            <list>
+              <option value="install" />
+              <option value="-DskipTests" />
+              <option value="-Dteavm.build.all=false" />
+            </list>
+          </option>
+          <option name="profilesMap">
+            <map />
+          </option>
+          <option name="resolveToWorkspace" value="false" />
+          <option name="workingDirPath" value="$PROJECT_DIR$" />
+        </MavenRunnerParameters>
+      </option>
+    </MavenSettings>
+    <method />
+  </configuration>
+</component>
\ No newline at end of file
diff --git a/metaprogramming/api/src/main/java/org/teavm/metaprogramming/ReflectClass.java b/metaprogramming/api/src/main/java/org/teavm/metaprogramming/ReflectClass.java
index 8b624190c..c7bdaae97 100644
--- a/metaprogramming/api/src/main/java/org/teavm/metaprogramming/ReflectClass.java
+++ b/metaprogramming/api/src/main/java/org/teavm/metaprogramming/ReflectClass.java
@@ -15,7 +15,6 @@
  */
 package org.teavm.metaprogramming;
 
-import java.util.Arrays;
 import org.teavm.metaprogramming.reflect.ReflectAnnotatedElement;
 import org.teavm.metaprogramming.reflect.ReflectField;
 import org.teavm.metaprogramming.reflect.ReflectMethod;
@@ -49,15 +48,9 @@ public interface ReflectClass<T> extends ReflectAnnotatedElement {
 
     <U> ReflectClass<U> asSubclass(Class<U> cls);
 
-    default boolean isAssignableFrom(ReflectClass<?> cls) {
-        return cls == this
-                || cls.getSuperclass() != null && this.isAssignableFrom(cls.getSuperclass())
-                || Arrays.stream(cls.getInterfaces()).anyMatch(this::isAssignableFrom);
-    }
+    boolean isAssignableFrom(ReflectClass<?> cls);
 
-    default boolean isAssignableFrom(Class<?> cls) {
-        return isAssignableFrom(Metaprogramming.findClass(cls));
-    }
+    boolean isAssignableFrom(Class<?> cls);
 
     ReflectMethod[] getDeclaredMethods();
 
@@ -65,21 +58,11 @@ public interface ReflectClass<T> extends ReflectAnnotatedElement {
 
     ReflectMethod getDeclaredMethod(String name, ReflectClass<?>... parameterTypes);
 
-    default ReflectMethod getDeclaredJMethod(String name, Class<?>... parameterTypes) {
-        ReflectClass<?>[] mappedParamTypes = Arrays.stream(parameterTypes)
-                .map(Metaprogramming::findClass)
-                .toArray(ReflectClass[]::new);
-        return getDeclaredMethod(name, mappedParamTypes);
-    }
+    ReflectMethod getDeclaredJMethod(String name, Class<?>... parameterTypes);
 
     ReflectMethod getMethod(String name, ReflectClass<?>... parameterTypes);
 
-    default ReflectMethod getJMethod(String name, Class<?>... parameterTypes) {
-        ReflectClass<?>[] mappedParamTypes = Arrays.stream(parameterTypes)
-                .map(Metaprogramming::findClass)
-                .toArray(ReflectClass[]::new);
-        return getMethod(name, mappedParamTypes);
-    }
+    ReflectMethod getJMethod(String name, Class<?>... parameterTypes);
 
     ReflectField[] getDeclaredFields();
 
diff --git a/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/reflect/ReflectClassImpl.java b/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/reflect/ReflectClassImpl.java
index dc95e5a65..af79d9e17 100644
--- a/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/reflect/ReflectClassImpl.java
+++ b/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/reflect/ReflectClassImpl.java
@@ -25,6 +25,7 @@ import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
 import org.teavm.metaprogramming.ReflectClass;
+import org.teavm.metaprogramming.impl.MetaprogrammingImpl;
 import org.teavm.metaprogramming.reflect.ReflectField;
 import org.teavm.metaprogramming.reflect.ReflectMethod;
 import org.teavm.model.AccessLevel;
@@ -197,6 +198,18 @@ public class ReflectClassImpl<T> implements ReflectClass<T> {
         return (ReflectClass<U>) this;
     }
 
+    @Override
+    public boolean isAssignableFrom(ReflectClass<?> cls) {
+        return cls == this
+                || cls.getSuperclass() != null && this.isAssignableFrom(cls.getSuperclass())
+                || Arrays.stream(cls.getInterfaces()).anyMatch(this::isAssignableFrom);
+    }
+
+    @Override
+    public boolean isAssignableFrom(Class<?> cls) {
+        return isAssignableFrom(MetaprogrammingImpl.findClass(cls));
+    }
+
     @Override
     public ReflectMethod[] getDeclaredMethods() {
         resolve();
@@ -273,6 +286,22 @@ public class ReflectClassImpl<T> implements ReflectClass<T> {
         });
     }
 
+    @Override
+    public ReflectMethod getDeclaredJMethod(String name, Class<?>... parameterTypes) {
+        ReflectClass<?>[] mappedParamTypes = Arrays.stream(parameterTypes)
+                .map(MetaprogrammingImpl::findClass)
+                .toArray(ReflectClass[]::new);
+        return getDeclaredMethod(name, mappedParamTypes);
+    }
+
+    @Override
+    public ReflectMethod getJMethod(String name, Class<?>... parameterTypes) {
+        ReflectClass<?>[] mappedParamTypes = Arrays.stream(parameterTypes)
+                .map(MetaprogrammingImpl::findClass)
+                .toArray(ReflectClass[]::new);
+        return getMethod(name, mappedParamTypes);
+    }
+
     @Override
     public ReflectMethod getMethod(String name, ReflectClass<?>... parameterTypes) {
         resolve();
diff --git a/tools/core/src/main/java/org/teavm/tooling/TeaVMProblemRenderer.java b/tools/core/src/main/java/org/teavm/tooling/TeaVMProblemRenderer.java
index e04669255..8288e45b7 100644
--- a/tools/core/src/main/java/org/teavm/tooling/TeaVMProblemRenderer.java
+++ b/tools/core/src/main/java/org/teavm/tooling/TeaVMProblemRenderer.java
@@ -59,7 +59,7 @@ public final class TeaVMProblemRenderer {
         renderCallLocation(location.getMethod(), location.getSourceLocation(), sb);
         if (location.getMethod() != null) {
             CallGraphNode node = cg.getNode(location.getMethod());
-            while (true) {
+            for (int i = 0; i < 100; ++i) {
                 Iterator<? extends CallSite> callSites = node.getCallerCallSites().iterator();
                 if (!callSites.hasNext()) {
                     break;