diff --git a/tools/cmd_dump_code.cpp b/tools/cmd_dump_code.cpp
index 6e217ad..681c30a 100644
--- a/tools/cmd_dump_code.cpp
+++ b/tools/cmd_dump_code.cpp
@@ -20,11 +20,13 @@
 #include <google/protobuf/text_format.h>
 #include <sys/stat.h>
 
+#include <cctype>
 #include <filesystem>
 #include <fstream>
 #include <iomanip>
 #include <iostream>
 #include <map>
+#include <set>
 #include <sstream>
 
 using namespace std;
@@ -53,7 +55,30 @@ static void create_parent_path(const std::string& path) {
 }
 static std::string mk_file_name(const std::string& dirname,
                                 const std::string& file) {
-  return dirname + "/" + file;
+  std::string safe;
+  safe.reserve(file.size());
+  for (char c : file) {
+    const bool unsafe = c == '/' || c == '\\' || c == ':' || c == '<' ||
+                        c == '>' || c == '"' || c == '|' || c == '?' ||
+                        c == '*';
+    safe.push_back(unsafe ? '_' : c);
+  }
+  CHECK(!safe.empty() && safe != "." && safe != "..")
+      << "invalid output filename derived from xmodel: " << file;
+#ifdef _WIN32
+  {
+    auto stem = safe.substr(0, safe.find('.'));
+    for (auto& ch : stem) ch = (char)::toupper((unsigned char)ch);
+    static const std::set<std::string> kReserved = {
+        "CON",  "PRN",  "AUX",  "NUL",  "COM1", "COM2", "COM3",
+        "COM4", "COM5", "COM6", "COM7", "COM8", "COM9", "LPT1",
+        "LPT2", "LPT3", "LPT4", "LPT5", "LPT6", "LPT7", "LPT8", "LPT9"};
+    if (kReserved.count(stem)) {
+      safe = "_" + safe;
+    }
+  }
+#endif
+  return dirname + "/" + safe;
 }
 
 static void dump_subgraph1(const xir::Subgraph* sg,