diff --git a/runtime/src/org/jetbrains/annotations/Mutable.java b/runtime/src/org/jetbrains/annotations/Mutable.java
new file mode 100644
index 00000000000..1dc6623a382
--- /dev/null
+++ b/runtime/src/org/jetbrains/annotations/Mutable.java
@@ -0,0 +1,29 @@
+/*
+ * Copyright 2010-2013 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.annotations;
+
+import java.lang.annotation.*;
+
+/**
+ * Annotate anything of type descendant from Iterable or Iterator with @Mutable if the corresponding collection/iterator
+ * is allowed to be mutated
+ */
+@Documented
+@Retention(RetentionPolicy.CLASS)
+@Target({ElementType.METHOD, ElementType.FIELD, ElementType.PARAMETER, ElementType.LOCAL_VARIABLE})
+public @interface Mutable {
+}
diff --git a/runtime/src/org/jetbrains/annotations/ReadOnly.java b/runtime/src/org/jetbrains/annotations/ReadOnly.java
new file mode 100644
index 00000000000..d061b36fdd0
--- /dev/null
+++ b/runtime/src/org/jetbrains/annotations/ReadOnly.java
@@ -0,0 +1,29 @@
+/*
+ * Copyright 2010-2013 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.annotations;
+
+import java.lang.annotation.*;
+
+/**
+ * Annotate anything of type descendant from Iterable or Iterator with @ReadOnly if the underlying reference is not intended for mutation.
+ * Note that such a reference is not guaranteed to be immutable. It may refer to an object mutated elsewhere.
+ */
+@Documented
+@Retention(RetentionPolicy.CLASS)
+@Target({ElementType.METHOD, ElementType.FIELD, ElementType.PARAMETER, ElementType.LOCAL_VARIABLE})
+public @interface ReadOnly {
+}