diff --git a/Changes b/Changes
index d605bbe74..08bbaffbd 100644
--- a/Changes
+++ b/Changes
@@ -18,6 +18,7 @@ Verilator 4.221 devel
 * Fix MSVC localtime_s (#3124).
 * Fix Bison 3.8.2 error (#3366). [elike-ypq]
 * Fix rare bug in -Oz (V3Localize) (#3286). [Geza Lore, Shunyao CAD]
+* Fix filenames with dots overwriting debug .vpp files (#3373).
 
 
 Verilator 4.220 2022-03-12
diff --git a/docs/guide/files.rst b/docs/guide/files.rst
index 522855ce3..796a4c756 100644
--- a/docs/guide/files.rst
+++ b/docs/guide/files.rst
@@ -120,7 +120,7 @@ In certain debug and other modes, it also creates:
      - Debugging graph files (from --debug)
    * - *{prefix}{misc}*\ .tree
      - Debugging files (from --debug)
-   * - {mod_prefix}_{each_verilog_module}*{__n}*\ .vpp
+   * - {mod_prefix}_{each_verilog_base_filename}*\ .vpp
      - Pre-processed verilog (from --debug)
 
 After running Make, the C++ compiler may produce the following:
diff --git a/src/V3ParseImp.cpp b/src/V3ParseImp.cpp
index 00ee4a53c..de03355ef 100644
--- a/src/V3ParseImp.cpp
+++ b/src/V3ParseImp.cpp
@@ -268,6 +268,7 @@ void V3ParseImp::preprocDumps(std::ostream& os) {
 
 void V3ParseImp::parseFile(FileLine* fileline, const string& modfilename, bool inLibrary,
                            const string& errmsg) {  // "" for no error, make fake node
+    const string nondirname = V3Os::filenameNonDir(modfilename);
     const string modname = V3Os::filenameNonExt(modfilename);
 
     UINFO(2, __FUNCTION__ << ": " << modname << (inLibrary ? " [LIB]" : "") << endl);
@@ -288,8 +289,8 @@ void V3ParseImp::parseFile(FileLine* fileline, const string& modfilename, bool i
 
     if (v3Global.opt.preprocOnly() || v3Global.opt.keepTempFiles()) {
         // Create output file with all the preprocessor output we buffered up
-        const string vppfilename
-            = v3Global.opt.hierTopDataDir() + "/" + v3Global.opt.prefix() + "_" + modname + ".vpp";
+        const string vppfilename = v3Global.opt.hierTopDataDir() + "/" + v3Global.opt.prefix()
+                                   + "_" + nondirname + ".vpp";
         std::ofstream* ofp = nullptr;
         std::ostream* osp;
         if (v3Global.opt.preprocOnly()) {