diff --git a/src/lib/dhcp/classify.cc b/src/lib/dhcp/classify.cc
index e234598e94..65cd8308ce 100644
--- a/src/lib/dhcp/classify.cc
+++ b/src/lib/dhcp/classify.cc
@@ -1,4 +1,4 @@
-// Copyright (C) 2014-2017 Internet Systems Consortium, Inc. ("ISC")
+// Copyright (C) 2014-2020 Internet Systems Consortium, Inc. ("ISC")
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -30,6 +30,12 @@ ClientClasses::ClientClasses(const std::string& class_names)
     }
 }
 
+void
+ClientClasses::erase(const ClientClass& class_name) {
+    list_.remove(class_name);
+    static_cast<void>(set_.erase(class_name));
+}
+
 std::string
 ClientClasses::toText(const std::string& separator) const {
     std::stringstream s;
diff --git a/src/lib/dhcp/classify.h b/src/lib/dhcp/classify.h
index 14614313fc..727e0cc402 100644
--- a/src/lib/dhcp/classify.h
+++ b/src/lib/dhcp/classify.h
@@ -1,4 +1,4 @@
-// Copyright (C) 2014-2017 Internet Systems Consortium, Inc. ("ISC")
+// Copyright (C) 2014-2020 Internet Systems Consortium, Inc. ("ISC")
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -64,6 +64,11 @@ namespace dhcp {
             set_.insert(class_name);
         }
 
+        /// @brief Erase element by name.
+        ///
+        /// @param class_name The name of the class to erase.
+        void erase(const ClientClass& class_name);
+
         /// @brief Check if classes is empty.
         bool empty() const {
             return (list_.empty());
diff --git a/src/lib/dhcp/tests/classify_unittest.cc b/src/lib/dhcp/tests/classify_unittest.cc
index 14e9d58443..938379cc88 100644
--- a/src/lib/dhcp/tests/classify_unittest.cc
+++ b/src/lib/dhcp/tests/classify_unittest.cc
@@ -1,4 +1,4 @@
-// Copyright (C) 2011-2017 Internet Systems Consortium, Inc. ("ISC")
+// Copyright (C) 2011-2020 Internet Systems Consortium, Inc. ("ISC")
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -131,3 +131,21 @@ TEST(ClassifyTest, ClientClassesToText) {
     // Check non-standard separator.
     EXPECT_EQ("alpha.gamma.beta", classes.toText("."));
 }
+
+// Check that selected class can be erased.
+TEST(ClassifyTest, Erase) {
+    ClientClasses classes;
+
+    classes.insert("alpha");
+    classes.insert("beta");
+    EXPECT_TRUE(classes.contains("alpha"));
+    EXPECT_TRUE(classes.contains("beta"));
+
+    classes.erase("beta");
+    EXPECT_TRUE(classes.contains("alpha"));
+    EXPECT_FALSE(classes.contains("beta"));
+
+    classes.erase("alpha");
+    EXPECT_FALSE(classes.contains("alpha"));
+    EXPECT_FALSE(classes.contains("beta"));
+}