diff --git a/modules/openapi-generator/src/main/resources/JavaSpring/enumClass.mustache b/modules/openapi-generator/src/main/resources/JavaSpring/enumClass.mustache
index 943a6822273f..c148ee898d34 100644
--- a/modules/openapi-generator/src/main/resources/JavaSpring/enumClass.mustache
+++ b/modules/openapi-generator/src/main/resources/JavaSpring/enumClass.mustache
@@ -55,6 +55,6 @@
           return b;
         }
       }
-      {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/isNullable}}
+      {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}{{#enumUnknownDefaultCase}}{{#allowableValues}}{{#enumVars}}{{#-last}}return {{{name}}};{{/-last}}{{/enumVars}}{{/allowableValues}}{{/enumUnknownDefaultCase}}{{^enumUnknownDefaultCase}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/enumUnknownDefaultCase}}{{/isNullable}}
     }
   }
diff --git a/modules/openapi-generator/src/main/resources/JavaSpring/enumOuterClass.mustache b/modules/openapi-generator/src/main/resources/JavaSpring/enumOuterClass.mustache
index 24c1057d9a8f..12c679ba993f 100644
--- a/modules/openapi-generator/src/main/resources/JavaSpring/enumOuterClass.mustache
+++ b/modules/openapi-generator/src/main/resources/JavaSpring/enumOuterClass.mustache
@@ -56,6 +56,6 @@ public enum {{{datatypeWithEnum}}}{{^datatypeWithEnum}}{{{classname}}}{{/datatyp
         return b;
       }
     }
-    {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/isNullable}}
+    {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}{{#enumUnknownDefaultCase}}{{#allowableValues}}{{#enumVars}}{{#-last}}return {{{name}}};{{/-last}}{{/enumVars}}{{/allowableValues}}{{/enumUnknownDefaultCase}}{{^enumUnknownDefaultCase}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/enumUnknownDefaultCase}}{{/isNullable}}
   }
 }
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/spring/SpringCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/spring/SpringCodegenTest.java
index 48fef733c943..cd7c21512dc9 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/spring/SpringCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/spring/SpringCodegenTest.java
@@ -4865,4 +4865,29 @@ public void shouldGenerateOptionalParameterTypesWhenUsingOptionalAndDelegate_iss
                 .toMethod()
                 .toFileAssert();
     }
+
+    @Test
+    public void testEnumUnknownDefaultCaseDeserializationTrue_issue13241() throws IOException {
+
+        SpringCodegen codegen = new SpringCodegen();
+        codegen.setLibrary(SPRING_BOOT);
+        codegen.additionalProperties().put(CodegenConstants.ENUM_UNKNOWN_DEFAULT_CASE, "true");
+
+        Map<String, File> files = generateFiles(codegen, "src/test/resources/bugs/issue_13241.yaml");
+
+        JavaFileAssert.assertThat(files.get("Color.java"))
+                .assertMethod("fromValue").bodyContainsLines("return UNKNOWN_DEFAULT_OPEN_API");
+    }
+
+    @Test
+    public void testEnumUnknownDefaultCaseDeserializationNotSet_issue13241() throws IOException {
+
+        SpringCodegen codegen = new SpringCodegen();
+        codegen.setLibrary(SPRING_BOOT);
+        Map<String, File> files = generateFiles(codegen, "src/test/resources/bugs/issue_13241.yaml");
+
+        JavaFileAssert.assertThat(files.get("Color.java"))
+                .assertMethod("fromValue").bodyContainsLines("throw new IllegalArgumentException(\"Unexpected value '\" + value + \"'\");");
+
+    }
 }
diff --git a/modules/openapi-generator/src/test/resources/bugs/issue_13241.yaml b/modules/openapi-generator/src/test/resources/bugs/issue_13241.yaml
new file mode 100644
index 000000000000..b30b61f19183
--- /dev/null
+++ b/modules/openapi-generator/src/test/resources/bugs/issue_13241.yaml
@@ -0,0 +1,17 @@
+openapi: "3.0.0"
+info:
+  version: 2.0.0
+  title: test
+paths:
+  /pets:
+    get:
+      summary: List all pets
+      operationId: listPets
+      responses:
+        '200':
+          description: OK
+components:
+  schemas:
+    Color:
+      type: string
+      enum: [RED, BLUE, GREEN]
\ No newline at end of file