diff --git a/docs/guide/files.rst b/docs/guide/files.rst
index 219979350..3928bd804 100644
--- a/docs/guide/files.rst
+++ b/docs/guide/files.rst
@@ -50,9 +50,9 @@ For --cc/--sc, it creates:
      - Make include file with class names (from --make gmake)
    * - *{prefix}*\ _hier.mk
      - Make file for hierarchy blocks (from --make gmake)
-   * - *{prefix}*\ _hierMkArgs.f
+   * - *{prefix}*\ __hierMkArgs.f
      - Arguments for hierarchical Verilation (from --make gmake)
-   * - *{prefix}*\ _hierCMakeArgs.f
+   * - *{prefix}*\ __hierCMakeArgs.f
      - Arguments for hierarchical Verilation (from --make cmake)
    * - *{prefix}*\ .h
      - Model header
diff --git a/src/V3HierBlock.cpp b/src/V3HierBlock.cpp
index 045647625..7b710aaef 100644
--- a/src/V3HierBlock.cpp
+++ b/src/V3HierBlock.cpp
@@ -90,7 +90,7 @@ VL_DEFINE_DEBUG_FUNCTIONS;
 
 static string V3HierCommandArgsFileName(const string& prefix, bool forCMake) {
     return v3Global.opt.makeDir() + "/" + prefix
-           + (forCMake ? "_hierCMakeArgs.f" : "_hierMkArgs.f");
+           + (forCMake ? "__hierCMakeArgs.f" : "__hierMkArgs.f");
 }
 
 static void V3HierWriteCommonInputs(const V3HierBlock* hblockp, std::ostream* of, bool forCMake) {