diff --git a/src/gmio_core/internal/fast_atof.h b/src/gmio_core/internal/fast_atof.h
index ee1afdd..c4bd95f 100644
--- a/src/gmio_core/internal/fast_atof.h
+++ b/src/gmio_core/internal/fast_atof.h
@@ -10,7 +10,7 @@
 #define GMIO_INTERNAL_FAST_ATOF_H
 
 #include "../global.h"
-#include "string_utils.h"
+#include "string_ascii_utils.h"
 
 #include <float.h>
 #include <limits.h>
diff --git a/src/gmio_core/internal/ascii_istrstr.c b/src/gmio_core/internal/string_ascii_istrstr.c
similarity index 98%
rename from src/gmio_core/internal/ascii_istrstr.c
rename to src/gmio_core/internal/string_ascii_istrstr.c
index 785ef9f..81ffc1a 100644
--- a/src/gmio_core/internal/ascii_istrstr.c
+++ b/src/gmio_core/internal/string_ascii_istrstr.c
@@ -13,7 +13,7 @@
 ** "http://www.cecill.info/licences/Licence_CeCILL-B_V1-en.html".
 ****************************************************************************/
 
-#include "string_utils.h"
+#include "string_ascii_utils.h"
 
 static int gmio_ascii_ustrincmp(
         const unsigned char* str1, const unsigned char* str2, size_t n)
diff --git a/src/gmio_core/internal/string_utils.h b/src/gmio_core/internal/string_ascii_utils.h
similarity index 97%
rename from src/gmio_core/internal/string_utils.h
rename to src/gmio_core/internal/string_ascii_utils.h
index b4ab399..ddecf0d 100644
--- a/src/gmio_core/internal/string_utils.h
+++ b/src/gmio_core/internal/string_ascii_utils.h
@@ -13,8 +13,8 @@
 ** "http://www.cecill.info/licences/Licence_CeCILL-B_V1-en.html".
 ****************************************************************************/
 
-#ifndef GMIO_INTERNAL_STRING_UTILS_H
-#define GMIO_INTERNAL_STRING_UTILS_H
+#ifndef GMIO_INTERNAL_STRING_ASCII_UTILS_H
+#define GMIO_INTERNAL_STRING_ASCII_UTILS_H
 
 #include "../global.h"
 
@@ -204,4 +204,4 @@ gmio_bool_t gmio_ascii_istarts_with(const char* str, const char* begin)
     return GMIO_TRUE;
 }
 
-#endif /* GMIO_INTERNAL_STRING_UTILS_H */
+#endif /* GMIO_INTERNAL_STRING_ASCII_UTILS_H */
diff --git a/src/gmio_core/internal/stringstream.h b/src/gmio_core/internal/stringstream.h
index c9f14bc..200109a 100644
--- a/src/gmio_core/internal/stringstream.h
+++ b/src/gmio_core/internal/stringstream.h
@@ -125,7 +125,7 @@ GMIO_INLINE gmio_float32_t gmio_to_float32(const char* str);
  */
 
 #include "helper_stream.h"
-#include "string_utils.h"
+#include "string_ascii_utils.h"
 #ifdef GMIO_STRINGSTREAM_USE_FAST_ATOF
 #  include "fast_atof.h"
 #  include "stringstream_fast_atof.h"
diff --git a/src/gmio_stl/internal/stla_infos_get.c b/src/gmio_stl/internal/stla_infos_get.c
index 2f254e4..dcc69ae 100644
--- a/src/gmio_stl/internal/stla_infos_get.c
+++ b/src/gmio_stl/internal/stla_infos_get.c
@@ -18,7 +18,7 @@
 #include "../../gmio_core/error.h"
 #include "../../gmio_core/internal/min_max.h"
 #include "../../gmio_core/internal/string.h"
-#include "../../gmio_core/internal/string_utils.h"
+#include "../../gmio_core/internal/string_ascii_utils.h"
 #include "stl_rw_common.h"
 
 #include <string.h>
diff --git a/src/gmio_stl/stl_format.c b/src/gmio_stl/stl_format.c
index 3448021..f565a4e 100644
--- a/src/gmio_stl/stl_format.c
+++ b/src/gmio_stl/stl_format.c
@@ -25,7 +25,7 @@
 #include "../gmio_core/internal/helper_stream.h"
 #include "../gmio_core/internal/min_max.h"
 #include "../gmio_core/internal/numeric_utils.h"
-#include "../gmio_core/internal/string_utils.h"
+#include "../gmio_core/internal/string_ascii_utils.h"
 
 #include <string.h>
 
diff --git a/src/gmio_stl/stla_read.c b/src/gmio_stl/stla_read.c
index df49ea6..84e1782 100644
--- a/src/gmio_stl/stla_read.c
+++ b/src/gmio_stl/stla_read.c
@@ -27,7 +27,7 @@
 #include "../gmio_core/internal/helper_stream.h"
 #include "../gmio_core/internal/min_max.h"
 #include "../gmio_core/internal/stringstream.h"
-#include "../gmio_core/internal/string_utils.h"
+#include "../gmio_core/internal/string_ascii_utils.h"
 
 #include <ctype.h>
 #include <stdlib.h>
diff --git a/tests/core_utils.h b/tests/core_utils.h
index f6c24d6..6707cd2 100644
--- a/tests/core_utils.h
+++ b/tests/core_utils.h
@@ -17,7 +17,7 @@
 #define GMIO_TESTS_CORE_UTILS_H
 
 #include "../src/gmio_core/global.h"
-#include "../src/gmio_core/internal/string_utils.h"
+#include "../src/gmio_core/internal/string_ascii_utils.h"
 
 #include <stddef.h>
 
diff --git a/tests/test_core_internal.c b/tests/test_core_internal.c
index 63c6715..9f419dd 100644
--- a/tests/test_core_internal.c
+++ b/tests/test_core_internal.c
@@ -25,7 +25,7 @@
 #include "../src/gmio_core/internal/safe_cast.h"
 #include "../src/gmio_core/internal/stringstream.h"
 #include "../src/gmio_core/internal/stringstream_fast_atof.h"
-#include "../src/gmio_core/internal/string_utils.h"
+#include "../src/gmio_core/internal/string_ascii_utils.h"
 
 #include <stdlib.h>
 #include <stdio.h>