diff --git a/spring-boot-project/spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/web/servlet/SpringBootMockMvcBuilderCustomizer.java b/spring-boot-project/spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/web/servlet/SpringBootMockMvcBuilderCustomizer.java
index 269d361500..d739a2766b 100644
--- a/spring-boot-project/spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/web/servlet/SpringBootMockMvcBuilderCustomizer.java
+++ b/spring-boot-project/spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/web/servlet/SpringBootMockMvcBuilderCustomizer.java
@@ -253,7 +253,7 @@ public class SpringBootMockMvcBuilderCustomizer implements MockMvcBuilderCustomi
 		}
 
 		void clear() {
-			this.lines.get().clear();
+			this.lines.remove();
 		}
 
 	}