diff --git a/debian/closure-compiler.1.txt b/debian/closure-compiler.1.txt
index 72abd567f9a..3009c7c8eda 100644
--- a/debian/closure-compiler.1.txt
+++ b/debian/closure-compiler.1.txt
@@ -359,6 +359,7 @@ require as a parameter a `WARNCLASS` warning class name. The following
 names are valid warning class names:
 
 * ``accessControls``
+* ``breakingOptionalChain``
 * ``checkRegExp``
 * ``checkTypes``
 * ``checkVars``
diff --git a/src/com/google/javascript/jscomp/DiagnosticGroups.java b/src/com/google/javascript/jscomp/DiagnosticGroups.java
index 850a8a64dc4..e6e57c225a9 100644
--- a/src/com/google/javascript/jscomp/DiagnosticGroups.java
+++ b/src/com/google/javascript/jscomp/DiagnosticGroups.java
@@ -120,6 +120,7 @@ public static DiagnosticGroup forName(String name) {
   // to parsing/ParserConfig.properties
   static final String DIAGNOSTIC_GROUP_NAMES =
       "accessControls, "
+          + "breakingOptionalChain, "
           + "checkPrototypalTypes, "
           + "checkRegExp, "
           + "checkTypes, "
@@ -500,6 +501,10 @@ public static DiagnosticGroup forName(String name) {
           ProcessCommonJSModules.SUSPICIOUS_EXPORTS_ASSIGNMENT,
           TypeCheck.DETERMINISTIC_TEST);
 
+  public static final DiagnosticGroup BREAKING_OPTIONAL_CHAIN =
+          DiagnosticGroups.registerGroup(
+                  "breakingOptionalChain", CheckSuspiciousCode.SUSPICIOUS_BREAKING_OUT_OF_OPTIONAL_CHAIN);
+
   public static final DiagnosticGroup FUNCTION_PARAMS =
       DiagnosticGroups.registerGroup(
           "functionParams",
diff --git a/src/com/google/javascript/jscomp/parsing/ParserConfig.properties b/src/com/google/javascript/jscomp/parsing/ParserConfig.properties
index 21d0c8fdd5d..935dfc654ce 100644
--- a/src/com/google/javascript/jscomp/parsing/ParserConfig.properties
+++ b/src/com/google/javascript/jscomp/parsing/ParserConfig.properties
@@ -162,6 +162,7 @@ jsdoc.annotations =\
 # This should be a subset of the list of DiagnosticGroups.
 jsdoc.suppressions =\
     accessControls,\
+    breakingOptionalChain,\
     checkDebuggerStatement,\
     checkEs5InheritanceCorrectnessConditions,\
     checkPrototypalTypes,\