--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Symbol.java	Fri Jan 26 16:38:21 2018 +0000
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Symbol.java	Fri Jan 26 11:27:53 2018 -0800
@@ -1889,7 +1889,7 @@
                     Name paramName = name.table.fromString("arg" + i);
                     VarSymbol param = new VarSymbol(PARAMETER, paramName, t, this);
                     newParams.append(param);
-
+                    i++;
                 }
                 params = newParams.toList();
             }

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/langtools/tools/javac/MethodParameters/DefaultParamNames.java	Fri Jan 26 11:27:53 2018 -0800
@@ -0,0 +1,77 @@
+/*
+ * Copyright 2017 Google Inc. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8194268
+ * @summary Incorrect parameter names for synthetic methods
+ * @modules jdk.compiler/com.sun.tools.javac.api
+ *          jdk.compiler/com.sun.tools.javac.code
+ *          jdk.compiler/com.sun.tools.javac.tree
+ *          jdk.compiler/com.sun.tools.javac.util
+ * @compile DefaultParamNames.java
+ * @run main DefaultParamNames
+ */
+
+import static java.util.stream.Collectors.joining;
+
+import com.sun.tools.javac.api.BasicJavacTask;
+import com.sun.tools.javac.code.Flags;
+import com.sun.tools.javac.code.Symbol.MethodSymbol;
+import com.sun.tools.javac.code.Symtab;
+import com.sun.tools.javac.code.Type.MethodType;
+import com.sun.tools.javac.util.Assert;
+import com.sun.tools.javac.util.Context;
+import com.sun.tools.javac.util.List;
+import com.sun.tools.javac.util.Names;
+import java.util.Objects;
+import javax.tools.JavaCompiler;
+import javax.tools.ToolProvider;
+
+public class DefaultParamNames {
+
+    public static void main(String[] args) {
+        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
+        BasicJavacTask task = (BasicJavacTask) compiler.getTask(null, null, null, null, null, null);
+        Context context = task.getContext();
+        Names names = Names.instance(context);
+        Symtab symtab = Symtab.instance(context);
+        MethodType mt =
+                new MethodType(
+                        List.of(symtab.intType, symtab.stringType, symtab.objectType),
+                        symtab.voidType,
+                        List.nil(),
+                        symtab.methodClass);
+        MethodSymbol ms =
+                new MethodSymbol(Flags.SYNTHETIC, names.fromString("test"), mt, symtab.methodClass);
+        String paramNames =
+                ms.params().stream().map(p -> p.getSimpleName().toString()).collect(joining(","));
+        assertEquals("arg0,arg1,arg2", paramNames);
+    }
+
+    static void assertEquals(Object expected, Object actual) {
+        Assert.check(
+                Objects.equals(expected, actual),
+                String.format("expected: %s, but was: %s", expected, actual));
+    }
+}