diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
index 0778fd527bba..ba9267db51b3 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
@@ -6330,7 +6330,7 @@ protected List<Map<String, Object>> buildEnumVars(List<Object> values, String da
             String commonPrefix = findCommonPrefixOfVars(values);
             truncateIdx = commonPrefix.length();
         }
-
+        Map<String, Integer> uniqueNames = new HashMap<>();
         for (Object value : values) {
             Map<String, Object> enumVar = new HashMap<>();
             String enumName;
@@ -6342,8 +6342,8 @@ protected List<Map<String, Object>> buildEnumVars(List<Object> values, String da
                     enumName = value.toString();
                 }
             }
-
-            enumVar.put("name", toEnumVarName(enumName, dataType));
+            String varName = toEnumVarName(enumName, dataType);
+            enumVar.put("name", ensureUniqueName(uniqueNames, varName));
             enumVar.put("value", toEnumValue(String.valueOf(value), dataType));
             enumVar.put("isString", isDataTypeString(dataType));
             enumVars.add(enumVar);
@@ -6377,6 +6377,19 @@ protected List<Map<String, Object>> buildEnumVars(List<Object> values, String da
         return enumVars;
     }
 
+    /**
+     * If necessary, appends a suffix to enforce uniqueness of names within a namespace.
+     * @param uniqueNames Counts name occurrences within a namespace.
+     * @param name The proposed name.
+     * @return <code>name</code>, uniquely suffixed as necessary.
+     */
+    protected String ensureUniqueName(Map<String, Integer> uniqueNames, String name) {
+        int count = uniqueNames.getOrDefault(name, 0) + 1 ;
+        if (uniqueNames.put(name, count) != null)
+            name = name + '_' + count;
+        return name;
+    }
+
     protected void updateEnumVarsWithExtensions(List<Map<String, Object>> enumVars, Map<String, Object> vendorExtensions, String dataType) {
         if (vendorExtensions != null) {
             updateEnumVarsWithExtensions(enumVars, vendorExtensions, "x-enum-varnames", "name");
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultCodegenTest.java
index 95dc96332992..119081de929c 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultCodegenTest.java
@@ -789,6 +789,53 @@ public void updateCodegenPropertyEnumWithoutPrefixRemoved() {
         Assert.assertEquals(enumVars.get(1).getOrDefault("value", ""), "\"animal_cat\"");
     }
 
+
+    @Test
+    public void updateCodegenPropertyEnumWithMultiByteChars() {
+        {
+            final DefaultCodegen codegen = new DefaultCodegen();
+            codegen.setRemoveEnumValuePrefix(false);
+
+            CodegenProperty enumProperty = codegenProperty(Arrays.asList("猫", "Пёс", "Χάμστερ"));
+
+            codegen.updateCodegenPropertyEnum(enumProperty);
+
+            List<Map<String, Object>> enumVars = (List<Map<String, Object>>) enumProperty.getItems().getAllowableValues().get("enumVars");
+
+            Assert.assertNotNull(enumVars);
+            Assert.assertNotNull(enumVars.get(0));
+            Assert.assertEquals(enumVars.get(0).getOrDefault("name", ""), "_");
+            Assert.assertEquals(enumVars.get(0).getOrDefault("value", ""), "\"猫\"");
+            Assert.assertNotNull(enumVars.get(1));
+            Assert.assertEquals(enumVars.get(1).getOrDefault("name", ""), "__2");
+            Assert.assertEquals(enumVars.get(1).getOrDefault("value", ""), "\"Пёс\"");
+            Assert.assertNotNull(enumVars.get(2));
+            Assert.assertEquals(enumVars.get(2).getOrDefault("name", ""), "__3");
+            Assert.assertEquals(enumVars.get(2).getOrDefault("value", ""), "\"Χάμστερ\"");
+        }
+        {
+            final DefaultCodegen codegen = new DefaultCodegen();
+            codegen.setRemoveEnumValuePrefix(false);
+
+            CodegenProperty enumProperty = codegenProperty(Arrays.asList("1ый квартал", "1ый день", "1ая смена"));
+
+            codegen.updateCodegenPropertyEnum(enumProperty);
+
+            List<Map<String, Object>> enumVars = (List<Map<String, Object>>) enumProperty.getItems().getAllowableValues().get("enumVars");
+
+            Assert.assertNotNull(enumVars);
+            Assert.assertNotNull(enumVars.get(0));
+            Assert.assertEquals(enumVars.get(0).getOrDefault("name", ""), "_1_");
+            Assert.assertEquals(enumVars.get(0).getOrDefault("value", ""), "\"1ый квартал\"");
+            Assert.assertNotNull(enumVars.get(1));
+            Assert.assertEquals(enumVars.get(1).getOrDefault("name", ""), "_1__2");
+            Assert.assertEquals(enumVars.get(1).getOrDefault("value", ""), "\"1ый день\"");
+            Assert.assertNotNull(enumVars.get(2));
+            Assert.assertEquals(enumVars.get(2).getOrDefault("name", ""), "_1__3");
+            Assert.assertEquals(enumVars.get(2).getOrDefault("value", ""), "\"1ая смена\"");
+        }
+    }
+
     @Test
     public void postProcessModelsEnumWithPrefixRemoved() {
         final DefaultCodegen codegen = new DefaultCodegen();
@@ -846,6 +893,48 @@ public void postProcessModelsEnumWithExtension() {
         Assert.assertEquals(enumVars.get(1).getOrDefault("enumDescription", ""), "This is a cat");
     }
 
+    @Test
+    public void postProcessModelsEnumWithMultiByteChars() {
+        {
+            final DefaultCodegen codegen = new DefaultCodegen();
+            ModelsMap objs = codegenModel(Arrays.asList("猫", "Пёс", "Χάμστερ"));
+            CodegenModel cm = objs.getModels().get(0).getModel();
+
+            codegen.postProcessModelsEnum(objs);
+
+            List<Map<String, Object>> enumVars = (List<Map<String, Object>>) cm.getAllowableValues().get("enumVars");
+            Assert.assertNotNull(enumVars);
+            Assert.assertNotNull(enumVars.get(0));
+            Assert.assertEquals(enumVars.get(0).getOrDefault("name", ""), "_");
+            Assert.assertEquals(enumVars.get(0).getOrDefault("value", ""), "\"猫\"");
+            Assert.assertNotNull(enumVars.get(1));
+            Assert.assertEquals(enumVars.get(1).getOrDefault("name", ""), "__2");
+            Assert.assertEquals(enumVars.get(1).getOrDefault("value", ""), "\"Пёс\"");
+            Assert.assertNotNull(enumVars.get(2));
+            Assert.assertEquals(enumVars.get(2).getOrDefault("name", ""), "__3");
+            Assert.assertEquals(enumVars.get(2).getOrDefault("value", ""), "\"Χάμστερ\"");
+        }
+        {
+            final DefaultCodegen codegen = new DefaultCodegen();
+            ModelsMap objs = codegenModel(Arrays.asList("1ый квартал", "1ый день", "1ая смена"));
+            CodegenModel cm = objs.getModels().get(0).getModel();
+
+            codegen.postProcessModelsEnum(objs);
+
+            List<Map<String, Object>> enumVars = (List<Map<String, Object>>) cm.getAllowableValues().get("enumVars");
+            Assert.assertNotNull(enumVars);
+            Assert.assertNotNull(enumVars.get(0));
+            Assert.assertEquals(enumVars.get(0).getOrDefault("name", ""), "_1_");
+            Assert.assertEquals(enumVars.get(0).getOrDefault("value", ""), "\"1ый квартал\"");
+            Assert.assertNotNull(enumVars.get(1));
+            Assert.assertEquals(enumVars.get(1).getOrDefault("name", ""), "_1__2");
+            Assert.assertEquals(enumVars.get(1).getOrDefault("value", ""), "\"1ый день\"");
+            Assert.assertNotNull(enumVars.get(2));
+            Assert.assertEquals(enumVars.get(2).getOrDefault("name", ""), "_1__3");
+            Assert.assertEquals(enumVars.get(2).getOrDefault("value", ""), "\"1ая смена\"");
+        }
+    }
+
     @Test
     public void testExample1() {
         final OpenAPI openAPI = TestUtils.parseFlattenSpec("src/test/resources/3_0/examples.yaml");