diff --git a/src/Standards/Generic/Sniffs/NamingConventions/InterfaceNameSuffixSniff.php b/src/Standards/Generic/Sniffs/NamingConventions/InterfaceNameSuffixSniff.php
index 637e036f1f..6dfad6b406 100644
--- a/src/Standards/Generic/Sniffs/NamingConventions/InterfaceNameSuffixSniff.php
+++ b/src/Standards/Generic/Sniffs/NamingConventions/InterfaceNameSuffixSniff.php
@@ -40,6 +40,7 @@ public function process(File $phpcsFile, $stackPtr)
     {
         $interfaceName = $phpcsFile->getDeclarationName($stackPtr);
         if ($interfaceName === null) {
+            // Live coding or parse error. Bow out.
             return;
         }
 
diff --git a/src/Standards/Generic/Tests/NamingConventions/InterfaceNameSuffixUnitTest.1.inc b/src/Standards/Generic/Tests/NamingConventions/InterfaceNameSuffixUnitTest.1.inc
new file mode 100644
index 0000000000..d09fa3df7d
--- /dev/null
+++ b/src/Standards/Generic/Tests/NamingConventions/InterfaceNameSuffixUnitTest.1.inc
@@ -0,0 +1,13 @@
+<?php
+
+interface SomeNameInterface {}
+
+interface MissingInterfaceSuffix {} // Error.
+
+interface CaseOfSuffixIsNotEnforced_interFACE {}
+
+interface
+    /*comment*/
+    InterfaceAnotherInvalidName
+    extends
+    AnotherInterface, \Countable {} // Error.
diff --git a/src/Standards/Generic/Tests/NamingConventions/InterfaceNameSuffixUnitTest.2.inc b/src/Standards/Generic/Tests/NamingConventions/InterfaceNameSuffixUnitTest.2.inc
new file mode 100644
index 0000000000..fcecfd007e
--- /dev/null
+++ b/src/Standards/Generic/Tests/NamingConventions/InterfaceNameSuffixUnitTest.2.inc
@@ -0,0 +1,7 @@
+<?php
+
+// Intentional parse error (no interface name).
+// This should be the only test in this file.
+// Testing that the sniff is *not* triggered.
+
+interface
diff --git a/src/Standards/Generic/Tests/NamingConventions/InterfaceNameSuffixUnitTest.inc b/src/Standards/Generic/Tests/NamingConventions/InterfaceNameSuffixUnitTest.inc
deleted file mode 100644
index d562d3eaeb..0000000000
--- a/src/Standards/Generic/Tests/NamingConventions/InterfaceNameSuffixUnitTest.inc
+++ /dev/null
@@ -1,27 +0,0 @@
-<?php
-
-interface SomeNameInterface
-{
-
-}
-
-interface ISomeName // error
-{
-
-}
-
-interface ISomeNameInterface
-{
-
-}
-
-
-interface ISomeOtherNameinterface
-{
-
-}
-
-interface mInterface
-{
-
-}
diff --git a/src/Standards/Generic/Tests/NamingConventions/InterfaceNameSuffixUnitTest.php b/src/Standards/Generic/Tests/NamingConventions/InterfaceNameSuffixUnitTest.php
index e5a4c3c597..1d89d1b35f 100644
--- a/src/Standards/Generic/Tests/NamingConventions/InterfaceNameSuffixUnitTest.php
+++ b/src/Standards/Generic/Tests/NamingConventions/InterfaceNameSuffixUnitTest.php
@@ -25,11 +25,21 @@ final class InterfaceNameSuffixUnitTest extends AbstractSniffUnitTest
      * The key of the array should represent the line number and the value
      * should represent the number of errors that should occur on that line.
      *
+     * @param string $testFile The name of the test file.
+     *
      * @return array<int, int>
      */
-    public function getErrorList()
+    public function getErrorList($testFile='')
     {
-        return [8 => 1];
+        switch ($testFile) {
+        case 'InterfaceNameSuffixUnitTest.1.inc':
+            return [
+                5 => 1,
+                9 => 1,
+            ];
+        default:
+            return [];
+        }
 
     }//end getErrorList()