diff --git a/api/envoy/admin/v2alpha/metrics.proto b/api/envoy/admin/v2alpha/metrics.proto
index c0b489f4e39b..9a91c7477be5 100644
--- a/api/envoy/admin/v2alpha/metrics.proto
+++ b/api/envoy/admin/v2alpha/metrics.proto
@@ -12,7 +12,6 @@ option java_package = "io.envoyproxy.envoy.admin.v2alpha";
 message SimpleMetric {
   enum Type {
     COUNTER = 0;
-
     GAUGE = 1;
   }
 
diff --git a/api/envoy/admin/v2alpha/server_info.proto b/api/envoy/admin/v2alpha/server_info.proto
index b43a6b23abd8..c2b44c06ca49 100644
--- a/api/envoy/admin/v2alpha/server_info.proto
+++ b/api/envoy/admin/v2alpha/server_info.proto
@@ -49,7 +49,6 @@ message ServerInfo {
 message CommandLineOptions {
   enum IpVersion {
     v4 = 0;
-
     v6 = 1;
   }
 
diff --git a/api/envoy/api/v2/cds.proto b/api/envoy/api/v2/cds.proto
index 884e94deb0cc..bca54c91b784 100644
--- a/api/envoy/api/v2/cds.proto
+++ b/api/envoy/api/v2/cds.proto
@@ -138,9 +138,7 @@ message Cluster {
   // ignored.
   enum DnsLookupFamily {
     AUTO = 0;
-
     V4_ONLY = 1;
-
     V6_ONLY = 2;
   }
 
@@ -185,9 +183,7 @@ message Cluster {
     // endpoints matching the values from the default_subset field.
     enum LbSubsetFallbackPolicy {
       NO_FALLBACK = 0;
-
       ANY_ENDPOINT = 1;
-
       DEFAULT_SUBSET = 2;
     }
 
diff --git a/api/envoy/api/v2/core/base.proto b/api/envoy/api/v2/core/base.proto
index 3388d31f4d7c..eca007605750 100644
--- a/api/envoy/api/v2/core/base.proto
+++ b/api/envoy/api/v2/core/base.proto
@@ -26,30 +26,20 @@ import "validate/validate.proto";
 // over a single upstream connection.
 enum RoutingPriority {
   DEFAULT = 0;
-
   HIGH = 1;
 }
 
 // HTTP request method.
 enum RequestMethod {
   METHOD_UNSPECIFIED = 0;
-
   GET = 1;
-
   HEAD = 2;
-
   POST = 3;
-
   PUT = 4;
-
   DELETE = 5;
-
   CONNECT = 6;
-
   OPTIONS = 7;
-
   TRACE = 8;
-
   PATCH = 9;
 }
 
diff --git a/api/envoy/api/v2/route/route.proto b/api/envoy/api/v2/route/route.proto
index aafcfcb0cfac..1678c0ef9020 100644
--- a/api/envoy/api/v2/route/route.proto
+++ b/api/envoy/api/v2/route/route.proto
@@ -499,7 +499,6 @@ message RouteAction {
   // Configures :ref:`internal redirect <arch_overview_internal_redirects>` behavior.
   enum InternalRedirectAction {
     PASS_THROUGH_INTERNAL_REDIRECT = 0;
-
     HANDLE_INTERNAL_REDIRECT = 1;
   }
 
diff --git a/api/envoy/config/filter/accesslog/v2/accesslog.proto b/api/envoy/config/filter/accesslog/v2/accesslog.proto
index 7464094fbf2c..8810e050e95f 100644
--- a/api/envoy/config/filter/accesslog/v2/accesslog.proto
+++ b/api/envoy/config/filter/accesslog/v2/accesslog.proto
@@ -209,37 +209,21 @@ message ResponseFlagFilter {
 message GrpcStatusFilter {
   enum Status {
     OK = 0;
-
     CANCELED = 1;
-
     UNKNOWN = 2;
-
     INVALID_ARGUMENT = 3;
-
     DEADLINE_EXCEEDED = 4;
-
     NOT_FOUND = 5;
-
     ALREADY_EXISTS = 6;
-
     PERMISSION_DENIED = 7;
-
     RESOURCE_EXHAUSTED = 8;
-
     FAILED_PRECONDITION = 9;
-
     ABORTED = 10;
-
     OUT_OF_RANGE = 11;
-
     UNIMPLEMENTED = 12;
-
     INTERNAL = 13;
-
     UNAVAILABLE = 14;
-
     DATA_LOSS = 15;
-
     UNAUTHENTICATED = 16;
   }
 
diff --git a/api/envoy/config/filter/http/gzip/v2/gzip.proto b/api/envoy/config/filter/http/gzip/v2/gzip.proto
index ac903b693121..6b3914751be2 100644
--- a/api/envoy/config/filter/http/gzip/v2/gzip.proto
+++ b/api/envoy/config/filter/http/gzip/v2/gzip.proto
@@ -16,20 +16,15 @@ import "validate/validate.proto";
 message Gzip {
   enum CompressionStrategy {
     DEFAULT = 0;
-
     FILTERED = 1;
-
     HUFFMAN = 2;
-
     RLE = 3;
   }
 
   message CompressionLevel {
     enum Enum {
       DEFAULT = 0;
-
       BEST = 1;
-
       SPEED = 2;
     }
   }
diff --git a/api/envoy/data/accesslog/v2/accesslog.proto b/api/envoy/data/accesslog/v2/accesslog.proto
index 0daebb6390e7..1cb7d13112e5 100644
--- a/api/envoy/data/accesslog/v2/accesslog.proto
+++ b/api/envoy/data/accesslog/v2/accesslog.proto
@@ -38,11 +38,8 @@ message HTTPAccessLogEntry {
   // HTTP version
   enum HTTPVersion {
     PROTOCOL_UNSPECIFIED = 0;
-
     HTTP10 = 1;
-
     HTTP11 = 2;
-
     HTTP2 = 3;
   }
 
@@ -239,13 +236,9 @@ message ResponseFlags {
 message TLSProperties {
   enum TLSVersion {
     VERSION_UNSPECIFIED = 0;
-
     TLSv1 = 1;
-
     TLSv1_1 = 2;
-
     TLSv1_2 = 3;
-
     TLSv1_3 = 4;
   }
 
diff --git a/api/envoy/data/core/v2alpha/health_check_event.proto b/api/envoy/data/core/v2alpha/health_check_event.proto
index 454461b23ce3..29c66421e112 100644
--- a/api/envoy/data/core/v2alpha/health_check_event.proto
+++ b/api/envoy/data/core/v2alpha/health_check_event.proto
@@ -17,19 +17,14 @@ import "validate/validate.proto";
 
 enum HealthCheckFailureType {
   ACTIVE = 0;
-
   PASSIVE = 1;
-
   NETWORK = 2;
 }
 
 enum HealthCheckerType {
   HTTP = 0;
-
   TCP = 1;
-
   GRPC = 2;
-
   REDIS = 3;
 }
 
diff --git a/tools/protoxform/protoxform.py b/tools/protoxform/protoxform.py
index 25e59dd185ab..6291e311eb52 100755
--- a/tools/protoxform/protoxform.py
+++ b/tools/protoxform/protoxform.py
@@ -363,10 +363,13 @@ def VisitService(self, service_proto, type_context):
 
   def VisitEnum(self, enum_proto, type_context):
     leading_comment, trailing_comment = FormatTypeContextComments(type_context)
-    values = '\n'.join(
+    values = [
         FormatEnumValue(type_context.ExtendField(index, value.name), value)
-        for index, value in enumerate(enum_proto.value))
-    return '%senum %s {\n%s%s\n}\n' % (leading_comment, enum_proto.name, trailing_comment, values)
+        for index, value in enumerate(enum_proto.value)
+    ]
+    joined_values = ('\n' if any('//' in v for v in values) else '').join(values)
+    return '%senum %s {\n%s%s\n}\n' % (leading_comment, enum_proto.name, trailing_comment,
+                                       joined_values)
 
   def VisitMessage(self, msg_proto, type_context, nested_msgs, nested_enums):
     leading_comment, trailing_comment = FormatTypeContextComments(type_context)