src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.options/src/org/graalvm/compiler/options/OptionValues.java

@@ -211,11 +211,11 @@
             if (value instanceof String) {
                 value = '"' + String.valueOf(value) + '"';
             }
 
             String name = namePrefix + e.getKey();
-            String assign = containsKey(desc.optionKey) ? ":=" : "=";
+            String assign = containsKey(desc.getOptionKey()) ? ":=" : "=";
             String typeName = desc.getOptionKey() instanceof EnumOptionKey ? "String" : desc.getOptionValueType().getSimpleName();
             String linePrefix = String.format("%s %s %s ", name, assign, value);
             int typeStartPos = PROPERTY_LINE_WIDTH - typeName.length();
             int linePad = typeStartPos - linePrefix.length();
             if (linePad > 0) {