diff --git a/core-java/pom.xml b/core-java/pom.xml
index 5766224b3a..3406bddda9 100644
--- a/core-java/pom.xml
+++ b/core-java/pom.xml
@@ -358,7 +358,7 @@
         <logback.version>1.1.7</logback.version>
 
         <!-- util -->
-        <guava.version>19.0</guava.version>
+        <guava.version>21.0</guava.version>
         <commons-lang3.version>3.5</commons-lang3.version>
         <bouncycastle.version>1.55</bouncycastle.version>
         <commons-codec.version>1.10</commons-codec.version>
diff --git a/core-java/src/test/java/com/baeldung/guava/GuavaBiMapTest.java b/core-java/src/test/java/com/baeldung/guava/GuavaBiMapTest.java
new file mode 100644
index 0000000000..c04cfb14fb
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/guava/GuavaBiMapTest.java
@@ -0,0 +1,122 @@
+package com.baeldung.guava;
+
+import static org.junit.Assert.*;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.junit.Test;
+import com.google.common.collect.BiMap;
+import com.google.common.collect.EnumHashBiMap;
+import com.google.common.collect.HashBiMap;
+import com.google.common.collect.ImmutableBiMap;
+
+public class GuavaBiMapTest {
+    @Test
+    public void whenQueryByValue_shouldReturnKey() {
+        final BiMap<String, String> personCountryHeadBiMap = HashBiMap.create();
+        personCountryHeadBiMap.put("Modi", "India");
+        personCountryHeadBiMap.put("Obama", "USA");
+        personCountryHeadBiMap.put("Putin", "USSR");
+
+        final String countryHeadName = personCountryHeadBiMap.inverse().get("India");
+
+        assertEquals("Modi", countryHeadName);
+    }
+
+    @Test
+    public void whenCreateBiMapFromExistingMap_shouldReturnKey() {
+        final Map<String, String> personCountryHeadMap = new HashMap<>();
+        personCountryHeadMap.put("Modi", "India");
+        personCountryHeadMap.put("Obama", "USA");
+        personCountryHeadMap.put("Putin", "USSR");
+        final BiMap<String, String> personCountryHeadBiMap = HashBiMap.create(personCountryHeadMap);
+
+        final String countryHeadName = personCountryHeadBiMap.inverse().get("India");
+
+        assertEquals("Modi", countryHeadName);
+    }
+
+    @Test
+    public void whenQueryByKey_shouldReturnValue() {
+        final BiMap<String, String> personCountryHeadBiMap = HashBiMap.create();
+
+        personCountryHeadBiMap.put("Modi", "India");
+        personCountryHeadBiMap.put("Obama", "USA");
+        personCountryHeadBiMap.put("Putin", "USSR");
+
+        assertEquals("USA", personCountryHeadBiMap.get("Obama"));
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void whenSameValueIsBeingPresent_shouldThrowException() {
+        final BiMap<String, String> personCountryHeadBiMap = HashBiMap.create();
+
+        personCountryHeadBiMap.put("Modi", "India");
+        personCountryHeadBiMap.put("Obama", "USA");
+        personCountryHeadBiMap.put("Putin", "USSR");
+        personCountryHeadBiMap.put("Trump", "USA");
+    }
+
+    @Test
+    public void givenSameValueIsBeingPresent_whenForcePutIsUsed_shouldCompleteSuccessfully() {
+        final BiMap<String, String> personCountryHeadBiMap = HashBiMap.create();
+
+        personCountryHeadBiMap.put("Modi", "India");
+        personCountryHeadBiMap.put("Obama", "USA");
+        personCountryHeadBiMap.put("Putin", "USSR");
+        personCountryHeadBiMap.forcePut("Trump", "USA");
+
+        assertEquals("USA", personCountryHeadBiMap.get("Trump"));
+        assertEquals("Trump", personCountryHeadBiMap.inverse().get("USA"));
+    }
+
+    @Test
+    public void whenSameKeyIsBeingPresent_shouldReplaceAlreadyPresent() {
+        final BiMap<String, String> personCountryHeadBiMap = HashBiMap.create();
+
+        personCountryHeadBiMap.put("Modi", "India");
+        personCountryHeadBiMap.put("Obama", "USA");
+        personCountryHeadBiMap.put("Putin", "USSR");
+        personCountryHeadBiMap.put("Obama", "HongKong");
+
+        assertEquals("HongKong", personCountryHeadBiMap.get("Obama"));
+    }
+
+    @Test
+    public void whenUsingImmutableBiMap_shouldAllowPutSuccessfully() {
+        final BiMap<String, String> personCountryHeadBiMap = new ImmutableBiMap.Builder<String, String>().put("Modi", "India").put("Obama", "USA").put("Putin", "USSR").build();
+
+        assertEquals("USA", personCountryHeadBiMap.get("Obama"));
+    }
+
+    @Test(expected = UnsupportedOperationException.class)
+    public void whenUsingImmutableBiMap_shouldNotAllowRemove() {
+        final BiMap<String, String> personCountryHeadBiMap = new ImmutableBiMap.Builder<String, String>().put("Modi", "India").put("Obama", "USA").put("Putin", "USSR").build();
+
+        personCountryHeadBiMap.remove("Modi");
+    }
+
+    @Test(expected = UnsupportedOperationException.class)
+    public void whenUsingImmutableBiMap_shouldNotAllowPut() {
+        final BiMap<String, String> personCountryHeadBiMap = new ImmutableBiMap.Builder<String, String>().put("Modi", "India").put("Obama", "USA").put("Putin", "USSR").build();
+
+        personCountryHeadBiMap.put("Trump", "USA");
+    }
+
+    private enum Operation {
+        ADD, SUBTRACT, MULTIPLY, DIVIDE
+    }
+
+    @Test
+    public void whenUsingEnumAsKeyInMap_shouldReplaceAlreadyPresent() {
+        final BiMap<Operation, String> operationStringBiMap = EnumHashBiMap.create(Operation.class);
+
+        operationStringBiMap.put(Operation.ADD, "Add");
+        operationStringBiMap.put(Operation.SUBTRACT, "Subtract");
+        operationStringBiMap.put(Operation.MULTIPLY, "Multiply");
+        operationStringBiMap.put(Operation.DIVIDE, "Divide");
+
+        assertEquals("Divide", operationStringBiMap.get(Operation.DIVIDE));
+    }
+}