diff --git a/dump_constants.cc b/dump_constants.cc
index 80c8664..f3d7074 100644
--- a/dump_constants.cc
+++ b/dump_constants.cc
@@ -15,10 +15,12 @@
 #include "libsyscalls.h"
 
 int main() {
+  // Numeric values are passed to std::cout via std::to_string() to avoid
+  // the use of 'bextr' asm instruction (when compiled with -march=bdver4).
   std::cout << "{\n";
-  std::cout << "  \"arch_nr\": " << MINIJAIL_ARCH_NR << ",\n";
+  std::cout << "  \"arch_nr\": " << std::to_string(MINIJAIL_ARCH_NR) << ",\n";
   std::cout << "  \"arch_name\": \"" << MINIJAIL_ARCH_NAME << "\",\n";
-  std::cout << "  \"bits\": " << MINIJAIL_ARCH_BITS << ",\n";
+  std::cout << "  \"bits\": " << std::to_string(MINIJAIL_ARCH_BITS) << ",\n";
   std::cout << "  \"syscalls\": {\n";
   bool first = true;
   for (const struct syscall_entry* entry = syscall_table; entry->name;
@@ -27,7 +29,7 @@
       first = false;
     else
       std::cout << ",\n";
-    std::cout << "    \"" << entry->name << "\": " << entry->nr;
+    std::cout << "    \"" << entry->name << "\": " << std::to_string(entry->nr);
   }
   std::cout << "\n  },\n";
   std::cout << "  \"constants\": {\n";
@@ -38,7 +40,8 @@
       first = false;
     else
       std::cout << ",\n";
-    std::cout << "    \"" << entry->name << "\": " << entry->value;
+    std::cout << "    \"" << entry->name << "\": "
+	      << std::to_string(entry->value);
   }
   std::cout << "\n  }\n";
   std::cout << "}\n";