diff --git a/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/JavaClientCodegen.java b/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/JavaClientCodegen.java
index 360dc9c0f2f0..df4f07e25e6a 100644
--- a/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/JavaClientCodegen.java
+++ b/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/JavaClientCodegen.java
@@ -426,7 +426,12 @@ public class JavaClientCodegen extends DefaultCodegen implements CodegenConfig {
     }
 
     private String toEnumVarName(String value) {
-        return value.replaceAll("\\W+", "_").toUpperCase();
+        String var = value.replaceAll("\\W+", "_").toUpperCase();
+        if (var.matches("\\d.*")) {
+            return "_" + var;
+        } else {
+            return var;
+        }
     }
 
     private CodegenModel reconcileInlineEnums(CodegenModel codegenModel, CodegenModel parentCodegenModel) {