diff --git a/src/main/java/org/cactoos/collection/CollectionEnvelope.java b/src/main/java/org/cactoos/collection/CollectionEnvelope.java
index fb28da3055..fc16a8285a 100644
--- a/src/main/java/org/cactoos/collection/CollectionEnvelope.java
+++ b/src/main/java/org/cactoos/collection/CollectionEnvelope.java
@@ -26,6 +26,7 @@
 import java.util.Collection;
 import java.util.Iterator;
 import org.cactoos.Scalar;
+import org.cactoos.iterator.Immutable;
 import org.cactoos.scalar.UncheckedScalar;
 
 /**
@@ -70,7 +71,7 @@ public final boolean isEmpty() {
 
     @Override
     public final Iterator<X> iterator() {
-        return this.col.value().iterator();
+        return new Immutable<>(this.col.value().iterator());
     }
 
     @Override
diff --git a/src/main/java/org/cactoos/iterator/Immutable.java b/src/main/java/org/cactoos/iterator/Immutable.java
new file mode 100644
index 0000000000..46eb050ef8
--- /dev/null
+++ b/src/main/java/org/cactoos/iterator/Immutable.java
@@ -0,0 +1,61 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017-2018 Yegor Bugayenko
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package org.cactoos.iterator;
+
+import java.util.Iterator;
+
+/**
+ * Iterator that doesn't allow removal of elements.
+ *
+ * <p>There is no thread-safety guarantee.</p>
+ *
+ * @param <T> Element type
+ * @since 0.32
+ */
+public final class Immutable<T> implements Iterator<T> {
+
+    /**
+     * Decorated iterator.
+     */
+    private final Iterator<T> iterator;
+
+    /**
+     * Ctor.
+     * @param iter Iterator to make immutable
+     */
+    public Immutable(final Iterator<T> iter) {
+        this.iterator = iter;
+    }
+
+    @Override
+    public boolean hasNext() {
+        return this.iterator.hasNext();
+    }
+
+    @Override
+    public T next() {
+        return this.iterator.next();
+    }
+
+}
diff --git a/src/test/java/org/cactoos/collection/CollectionEnvelopeTest.java b/src/test/java/org/cactoos/collection/CollectionEnvelopeTest.java
new file mode 100644
index 0000000000..58d4f27e74
--- /dev/null
+++ b/src/test/java/org/cactoos/collection/CollectionEnvelopeTest.java
@@ -0,0 +1,54 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017-2018 Yegor Bugayenko
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package org.cactoos.collection;
+
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import org.junit.Test;
+
+/**
+ * Test case for {@link CollectionEnvelope}.
+ *
+ * @since 0.32
+ * @todo #813:30min IterableEnvelope appears to be read only but it returns
+ *  mutable Iterator through which user can remove elements. Implement immutable
+ *  Iterator for IterableEnvelope `iterator()` method.
+ * @checkstyle JavadocMethodCheck (500 lines)
+ */
+public final class CollectionEnvelopeTest {
+    @Test(expected = UnsupportedOperationException.class)
+    public void returnsIteratorWithUnsupportedRemove() {
+        final CollectionEnvelope<String> list = new CollectionEnvelope<String>(
+            () -> {
+                final List<String> inner = new LinkedList<>();
+                inner.add("eleven");
+                return inner;
+            }
+        ) { };
+        final Iterator<String> iterator = list.iterator();
+        iterator.next();
+        iterator.remove();
+    }
+}
diff --git a/src/test/java/org/cactoos/iterator/ImmutableTest.java b/src/test/java/org/cactoos/iterator/ImmutableTest.java
new file mode 100644
index 0000000000..336d5f6230
--- /dev/null
+++ b/src/test/java/org/cactoos/iterator/ImmutableTest.java
@@ -0,0 +1,69 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017-2018 Yegor Bugayenko
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package org.cactoos.iterator;
+
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Random;
+import org.hamcrest.MatcherAssert;
+import org.hamcrest.core.IsEqual;
+import org.junit.Test;
+
+/**
+ * Test Case for {@link Immutable}.
+ *
+ * @since 0.32
+ * @checkstyle JavadocMethodCheck (500 lines)
+ */
+public final class ImmutableTest {
+    @Test(expected = UnsupportedOperationException.class)
+    public void doesNotAllowRemovingOfElements() {
+        final List<String> list = new LinkedList<>();
+        list.add("one");
+        final Iterator<String> immutable = new Immutable<>(list.iterator());
+        immutable.next();
+        immutable.remove();
+    }
+
+    @Test
+    public void decoratesNext() {
+        final int value = new Random().nextInt();
+        final Iterator<Integer> immutable = new Immutable<>(
+            new IteratorOf<>(value)
+        );
+        MatcherAssert.assertThat(immutable.next(), new IsEqual<>(value));
+    }
+
+    @Test
+    public void decoratesHasNext() {
+        final int value = new Random().nextInt();
+        final Iterator<Integer> immutable = new Immutable<>(
+            new IteratorOf<>(value)
+        );
+        MatcherAssert.assertThat(immutable.hasNext(), new IsEqual<>(true));
+        immutable.next();
+        MatcherAssert.assertThat(immutable.hasNext(), new IsEqual<>(false));
+    }
+}