diff --git a/lib/Doctrine/ruleset.xml b/lib/Doctrine/ruleset.xml
index c0bf70bd..7c09d6fd 100644
--- a/lib/Doctrine/ruleset.xml
+++ b/lib/Doctrine/ruleset.xml
@@ -42,6 +42,8 @@
     <rule ref="Generic.CodeAnalysis.UselessOverridingMethod"/>
     <!-- Forbid inline HTML in PHP code -->
     <rule ref="Generic.Files.InlineHTML"/>
+    <!-- Only one structure (class/interface/trait) should be allowed per file -->
+    <rule ref="Generic.Files.OneObjectStructurePerFile" />
     <!-- Align corresponding assignment statement tokens -->
     <rule ref="Generic.Formatting.MultipleStatementAlignment">
         <properties>
diff --git a/tests/expected_report.txt b/tests/expected_report.txt
index fd6c01c0..c7c05201 100644
--- a/tests/expected_report.txt
+++ b/tests/expected_report.txt
@@ -6,7 +6,7 @@ FILE                                                  ERRORS  WARNINGS
 tests/input/array_indentation.php                     10      0
 tests/input/arrow-functions-format.php                10      0
 tests/input/assignment-operators.php                  4       0
-tests/input/class-references.php                      10      0
+tests/input/class-references.php                      11      0
 tests/input/concatenation_spacing.php                 24      0
 tests/input/constants-no-lsb.php                      2       0
 tests/input/constants-var.php                         6       0
@@ -31,10 +31,10 @@ tests/input/return_type_on_methods.php                17      0
 tests/input/semicolon_spacing.php                     3       0
 tests/input/spread-operator.php                       6       0
 tests/input/static-closures.php                       1       0
-tests/input/superfluous-naming.php                    11      0
+tests/input/superfluous-naming.php                    14      0
 tests/input/test-case.php                             8       0
 tests/input/trailing_comma_on_array.php               1       0
-tests/input/traits-uses.php                           11      0
+tests/input/traits-uses.php                           12      0
 tests/input/type-hints.php                            4       0
 tests/input/UnusedVariables.php                       1       0
 tests/input/use-ordering.php                          1       0
diff --git a/tests/php-compatibility.patch b/tests/php-compatibility.patch
index 68009098..12b6c185 100644
--- a/tests/php-compatibility.patch
+++ b/tests/php-compatibility.patch
@@ -8,7 +8,7 @@ index 1e809f9..490fcbd 100644
  tests/input/arrow-functions-format.php                10      0
  tests/input/assignment-operators.php                  4       0
 +tests/input/binary_operators.php                      9       0
- tests/input/class-references.php                      10      0
+ tests/input/class-references.php                      11      0
 -tests/input/concatenation_spacing.php                 24      0
 +tests/input/concatenation_spacing.php                 49      0
  tests/input/constants-no-lsb.php                      2       0
@@ -21,7 +21,7 @@ index 1e809f9..490fcbd 100644
 -tests/input/example-class.php                         34      0
 -tests/input/forbidden-comments.php                    8       0
 +tests/input/example-class.php                         39      0
-+tests/input/forbidden-comments.php                    14      0
++tests/input/forbidden-comments.php                    16      0
  tests/input/forbidden-functions.php                   6       0
  tests/input/inline_type_hint_assertions.php           7       0
  tests/input/LowCaseTypes.php                          2       0
@@ -42,10 +42,10 @@ index 1e809f9..490fcbd 100644
 +tests/input/single-line-array-spacing.php             5       0
  tests/input/spread-operator.php                       6       0
  tests/input/static-closures.php                       1       0
- tests/input/superfluous-naming.php                    11      0
+ tests/input/superfluous-naming.php                    14      0
  tests/input/test-case.php                             8       0
  tests/input/trailing_comma_on_array.php               1       0
- tests/input/traits-uses.php                           11      0
+ tests/input/traits-uses.php                           12      0
 -tests/input/type-hints.php                            4       0
 +tests/input/type-hints.php                            5       0
  tests/input/UnusedVariables.php                       1       0
@@ -54,7 +54,7 @@ index 1e809f9..490fcbd 100644
  tests/input/UselessConditions.php                     20      0
  ----------------------------------------------------------------------
 -A TOTAL OF 310 ERRORS AND 0 WARNINGS WERE FOUND IN 37 FILES
-+A TOTAL OF 384 ERRORS AND 0 WARNINGS WERE FOUND IN 41 FILES
++A TOTAL OF 391 ERRORS AND 0 WARNINGS WERE FOUND IN 41 FILES
  ----------------------------------------------------------------------
 -PHPCBF CAN FIX 249 OF THESE SNIFF VIOLATIONS AUTOMATICALLY
 +PHPCBF CAN FIX 319 OF THESE SNIFF VIOLATIONS AUTOMATICALLY