diff --git a/src/test/java/picocli/CommandLineTypeConversionTest.java b/src/test/java/picocli/CommandLineTypeConversionTest.java
index 126c31770..0ff4d7d21 100644
--- a/src/test/java/picocli/CommandLineTypeConversionTest.java
+++ b/src/test/java/picocli/CommandLineTypeConversionTest.java
@@ -511,7 +511,7 @@ private void parseInvalidValue(String option, String value, String... errorMessa
                 if (actual.getMessage().equals(errMsg)) { return; } // that is okay also
             }
             String type = option.substring(1);
-            String expected = String.format("Invalid value for option '%s': cannot convert '%s' to %s (%s)", option, value, type, errorMessage[0]);
+            String expected = String.format("Invalid value for option '%s': cannot convert '%s' to %s (%s", option, value, type, errorMessage[0]);
             assertTrue("expected:<" + expected + "> but was:<" + actual.getMessage() + ">",
                     actual.getMessage().startsWith(expected));
         }