diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2d325a7..1a6560d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -27,6 +27,7 @@ add_library(
     babylon
     SHARED
     src/babylon.cpp
+    src/cleaners.cpp
     src/phonemizer.cpp
     src/voice.cpp
 )
diff --git a/include/babylon.hpp b/include/babylon.hpp
index 06fc59e..167809c 100644
--- a/include/babylon.hpp
+++ b/include/babylon.hpp
@@ -50,6 +50,8 @@ namespace DeepPhonemizer {
 
       std::vector<std::string> g2p_internal(const std::string& text);
   };
+
+  std::vector<std::string> numbers_to_words(const std::string& text);
 }
 
 namespace Vits {
diff --git a/src/numbers_to_words.hpp b/src/cleaners.cpp
similarity index 78%
rename from src/numbers_to_words.hpp
rename to src/cleaners.cpp
index 454a63d..a0eb5b6 100644
--- a/src/numbers_to_words.hpp
+++ b/src/cleaners.cpp
@@ -134,31 +134,33 @@ std::string hundreds_to_words(int hundreds) {
     return result;
 }
 
-std::vector<std::string> numbers_to_words(const std::string& text) {
-    std::vector<std::string> result;
-    std::vector<std::string> parts = split_into_threes(text);
-    std::vector<std::string> suffixes = {
-        "thousand", 
-        "million", 
-        "billion", 
-        "trillion", 
-        "quadrillion", 
-        "quintillion",
-        "sextillion",
-        "septillion",
-        "octillion",
-        "nonillion",
-        "decillion"
-    };
-
-    for (int i = 0; i < parts.size(); i++) {
-        int number = std::stoi(parts[i]);
-        result.push_back(hundreds_to_words(number));
-
-        if (i > 0 && i < suffixes.size()) {
-            result.back() += " " + suffixes[i - 1];
+namespace DeepPhonemizer {
+    std::vector<std::string> numbers_to_words(const std::string& text) {
+        std::vector<std::string> result;
+        std::vector<std::string> parts = split_into_threes(text);
+        std::vector<std::string> suffixes = {
+            "thousand", 
+            "million", 
+            "billion", 
+            "trillion", 
+            "quadrillion", 
+            "quintillion",
+            "sextillion",
+            "septillion",
+            "octillion",
+            "nonillion",
+            "decillion"
+        };
+
+        for (int i = 0; i < parts.size(); i++) {
+            int number = std::stoi(parts[i]);
+            result.push_back(hundreds_to_words(number));
+
+            if (i > 0 && i < suffixes.size()) {
+                result.back() += " " + suffixes[i - 1];
+            }
         }
-    }
 
-    return result;
+        return result;
+    }
 }
\ No newline at end of file
diff --git a/src/phonemizer.cpp b/src/phonemizer.cpp
index 4968ec8..4ecd2b6 100644
--- a/src/phonemizer.cpp
+++ b/src/phonemizer.cpp
@@ -4,7 +4,6 @@
 #include <sstream>
 #include <algorithm>
 #include <cmath>
-#include "numbers_to_words.hpp"
 
 namespace DeepPhonemizer {
     SequenceTokenizer::SequenceTokenizer(const std::vector<std::string>& symbols, const std::vector<std::string>& languages, int char_repeats, bool lowercase, bool append_start_end)