diff --git a/spring-context/src/test/java/org/springframework/context/aot/ApplicationContextAotGeneratorTests.java b/spring-context/src/test/java/org/springframework/context/aot/ApplicationContextAotGeneratorTests.java
index 81767e3cfe..d02d504ee8 100644
--- a/spring-context/src/test/java/org/springframework/context/aot/ApplicationContextAotGeneratorTests.java
+++ b/spring-context/src/test/java/org/springframework/context/aot/ApplicationContextAotGeneratorTests.java
@@ -363,8 +363,8 @@ class ApplicationContextAotGeneratorTests {
 			applicationContext.registerBean(CglibConfiguration.class);
 			TestGenerationContext context = processAheadOfTime(applicationContext);
 			isRegisteredCglibClass(context, CglibConfiguration.class.getName() + "$$SpringCGLIB$$0");
-			isRegisteredCglibClass(context, CglibConfiguration.class.getName() + "$$SpringCGLIB$$1");
-			isRegisteredCglibClass(context, CglibConfiguration.class.getName() + "$$SpringCGLIB$$2");
+			isRegisteredCglibClass(context, CglibConfiguration.class.getName() + "$$SpringCGLIB$$FastClass$$0");
+			isRegisteredCglibClass(context, CglibConfiguration.class.getName() + "$$SpringCGLIB$$FastClass$$1");
 		}
 
 		private void isRegisteredCglibClass(TestGenerationContext context, String cglibClassName) throws IOException {
diff --git a/spring-core/src/main/java/org/springframework/cglib/core/SpringNamingPolicy.java b/spring-core/src/main/java/org/springframework/cglib/core/SpringNamingPolicy.java
index 7eb96dd701..347975a0e0 100644
--- a/spring-core/src/main/java/org/springframework/cglib/core/SpringNamingPolicy.java
+++ b/spring-core/src/main/java/org/springframework/cglib/core/SpringNamingPolicy.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -25,13 +25,17 @@ package org.springframework.cglib.core;
  * in the classpath.
  *
  * @author Juergen Hoeller
+ * @author Sam Brannen
  * @since 3.2.8 / 6.0
  */
 public final class SpringNamingPolicy implements NamingPolicy {
 
 	public static final SpringNamingPolicy INSTANCE = new SpringNamingPolicy();
 
-	private static final String LABEL = "$$SpringCGLIB$$";
+	private static final String SPRING_LABEL = "$$SpringCGLIB$$";
+
+	private static final String FAST_CLASS_SUFFIX = "FastClass$$";
+
 
 	private SpringNamingPolicy() {
 	}
@@ -46,12 +50,19 @@ public final class SpringNamingPolicy implements NamingPolicy {
 		}
 
 		String base;
-		int existingLabel = prefix.indexOf(LABEL);
+		int existingLabel = prefix.indexOf(SPRING_LABEL);
 		if (existingLabel >= 0) {
-			base = prefix.substring(0, existingLabel + LABEL.length());
+			base = prefix.substring(0, existingLabel + SPRING_LABEL.length());
 		}
 		else {
-			base = prefix + LABEL;
+			base = prefix + SPRING_LABEL;
+		}
+
+		// When the generated class name is for a FastClass, the source is
+		// "org.springframework.cglib.reflect.FastClass".
+		boolean isFastClass = (source != null && source.endsWith(".FastClass"));
+		if (isFastClass && !prefix.contains(FAST_CLASS_SUFFIX)) {
+			base += FAST_CLASS_SUFFIX;
 		}
 
 		int index = 0;
diff --git a/spring-core/src/test/java/org/springframework/cglib/core/SpringNamingPolicyTests.java b/spring-core/src/test/java/org/springframework/cglib/core/SpringNamingPolicyTests.java
new file mode 100644
index 0000000000..6f3e32e58d
--- /dev/null
+++ b/spring-core/src/test/java/org/springframework/cglib/core/SpringNamingPolicyTests.java
@@ -0,0 +1,91 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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.springframework.cglib.core;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.cglib.reflect.FastClass;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link SpringNamingPolicy}.
+ *
+ * @author Sam Brannen
+ * @since 6.0.13
+ */
+class SpringNamingPolicyTests {
+
+	private final Set<String> reservedClassNames = new HashSet<>();
+
+
+	@Test
+	void nullPrefix() {
+		assertThat(getClassName(null)).isEqualTo("org.springframework.cglib.empty.Object$$SpringCGLIB$$0");
+		assertThat(getClassName(null)).isEqualTo("org.springframework.cglib.empty.Object$$SpringCGLIB$$1");
+	}
+
+	@Test
+	void javaPrefix() {
+		assertThat(getClassName("java.util.ArrayList")).isEqualTo("_java.util.ArrayList$$SpringCGLIB$$0");
+		assertThat(getClassName("java.util.ArrayList")).isEqualTo("_java.util.ArrayList$$SpringCGLIB$$1");
+	}
+
+	@Test
+	void javaxPrefix() {
+		assertThat(getClassName("javax.sql.RowSet")).isEqualTo("_javax.sql.RowSet$$SpringCGLIB$$0");
+		assertThat(getClassName("javax.sql.RowSet")).isEqualTo("_javax.sql.RowSet$$SpringCGLIB$$1");
+	}
+
+	@Test
+	void examplePrefix() {
+		assertThat(getClassName("example.MyComponent")).isEqualTo("example.MyComponent$$SpringCGLIB$$0");
+		assertThat(getClassName("example.MyComponent")).isEqualTo("example.MyComponent$$SpringCGLIB$$1");
+	}
+
+	@Test
+	void prefixContainingSpringLabel() {
+		String generated1 = "example.MyComponent$$SpringCGLIB$$0";
+		String generated2 = "example.MyComponent$$SpringCGLIB$$1";
+
+		assertThat(getClassName(generated1)).isEqualTo(generated1);
+		assertThat(getClassName(generated1)).isEqualTo(generated2);
+	}
+
+	@Test
+	void fastClass() {
+		String prefix = "example.MyComponent";
+		String source = FastClass.class.getName();
+		assertThat(getClassName(prefix, "a.b.c", null)).isEqualTo("example.MyComponent$$SpringCGLIB$$0");
+		assertThat(getClassName(prefix, source, null)).isEqualTo("example.MyComponent$$SpringCGLIB$$FastClass$$0");
+		assertThat(getClassName(prefix, source, null)).isEqualTo("example.MyComponent$$SpringCGLIB$$FastClass$$1");
+	}
+
+	private String getClassName(String prefix) {
+		return getClassName(prefix, null, null);
+	}
+
+	private String getClassName(String prefix, String source, Object key) {
+		String className = SpringNamingPolicy.INSTANCE.getClassName(prefix, source, key, reservedClassNames::contains);
+		reservedClassNames.add(className);
+		return className;
+	}
+
+}