diff --git a/core/modules/locale/tests/locale_test.es6.js b/core/modules/locale/tests/locale_test.es6.js
index ba62b7504e..1f266c6239 100644
--- a/core/modules/locale/tests/locale_test.es6.js
+++ b/core/modules/locale/tests/locale_test.es6.js
@@ -50,3 +50,5 @@ Drupal.formatPlural(1, "Context Single Quoted plural", "Context Single Quoted @c
 Drupal.formatPlural(1, "Context Double Quoted plural", "Context Double Quoted @count plural", {}, {"context": "Context string double quoted"});
 
 Drupal.formatPlural(1, "Context !key Args plural", "Context !key Args @count plural", {'!key': 'value'}, {context: "Context string"});
+
+Drupal.formatPlural(1, "No count argument plural - singular", "No count argument plural - plural");
diff --git a/core/modules/locale/tests/locale_test.js b/core/modules/locale/tests/locale_test.js
index 86acc4a13c..42e435040e 100644
--- a/core/modules/locale/tests/locale_test.js
+++ b/core/modules/locale/tests/locale_test.js
@@ -35,4 +35,6 @@ Drupal.formatPlural(1, "Context Unquoted plural", "Context Unquoted @count plura
 Drupal.formatPlural(1, "Context Single Quoted plural", "Context Single Quoted @count plural", {}, { 'context': "Context string single quoted" });
 Drupal.formatPlural(1, "Context Double Quoted plural", "Context Double Quoted @count plural", {}, { "context": "Context string double quoted" });
 
-Drupal.formatPlural(1, "Context !key Args plural", "Context !key Args @count plural", { '!key': 'value' }, { context: "Context string" });
\ No newline at end of file
+Drupal.formatPlural(1, "Context !key Args plural", "Context !key Args @count plural", { '!key': 'value' }, { context: "Context string" });
+
+Drupal.formatPlural(1, "No count argument plural - singular", "No count argument plural - plural");
diff --git a/core/modules/locale/tests/src/Functional/LocaleJavascriptTranslationTest.php b/core/modules/locale/tests/src/Functional/LocaleJavascriptTranslationTest.php
index 1d6fde703b..11c0e530b5 100644
--- a/core/modules/locale/tests/src/Functional/LocaleJavascriptTranslationTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleJavascriptTranslationTest.php
@@ -85,6 +85,8 @@ public function testFileParsing() {
         "Context Unquoted plural{$etx}Context Unquoted @count plural" => 'Context string unquoted',
         "Context Single Quoted plural{$etx}Context Single Quoted @count plural" => 'Context string single quoted',
         "Context Double Quoted plural{$etx}Context Double Quoted @count plural" => 'Context string double quoted',
+
+        "No count argument plural - singular{$etx}No count argument plural - plural" => '',
       ];
 
       // Assert that all strings were found properly.