diff --git a/src/gmio_core/config.h.cmake b/src/gmio_core/config.h.cmake
index 5150a05..a5a937c 100644
--- a/src/gmio_core/config.h.cmake
+++ b/src/gmio_core/config.h.cmake
@@ -58,9 +58,18 @@
 #  define GMIO_TARGET_ARCH_BIT_SIZE  @GMIO_TARGET_ARCH_BIT_SIZE@
 #endif
 
-/* gmio_core/internal/string_parse.h */
-#ifndef GMIO_USE_FAST_ATOF
-#  define GMIO_USE_FAST_ATOF
+/* Header: gmio_core/internal/string_parse.h */
+#ifndef GMIO_STRINGPARSE_USE_FAST_ATOF
+/* Use fast_atof() instead of std string-to-float functions */
+#  define GMIO_STRINGPARSE_USE_FAST_ATOF
 #endif
 
+/* Header: gmio_core/internal/string_utils.h */
+#ifndef GMIO_STRINGUTILS_DIRECT_TESTS
+/* Use implementation based on "direct testing" */
+#  define GMIO_STRINGUTILS_DIRECT_TESTS
+#endif
+/*#define GMIO_STRINGUTILS_C_ARRAYS*/
+/*#define GMIO_STRINGUTILS_CTYPE_H*/
+
 #endif /* GMIO_CONFIG_H_CMAKE */
diff --git a/src/gmio_core/internal/string_parse.h b/src/gmio_core/internal/string_parse.h
index 27d80f5..9124602 100644
--- a/src/gmio_core/internal/string_parse.h
+++ b/src/gmio_core/internal/string_parse.h
@@ -22,7 +22,7 @@
 /* For implementation section */
 #include "helper_stream.h"
 #include "string_utils.h"
-#ifdef GMIO_USE_FAST_ATOF
+#ifdef GMIO_STRINGPARSE_USE_FAST_ATOF
 #  include "fast_atof.h"
 #endif
 
@@ -145,7 +145,7 @@ const char* gmio_skip_spaces(
 
 int gmio_get_float32(const char* str, gmio_float32_t* value_ptr)
 {
-#if defined(GMIO_USE_FAST_ATOF)
+#if defined(GMIO_STRINGPARSE_USE_FAST_ATOF)
     const char* end_ptr = NULL;
     *value_ptr = fast_atof(str, &end_ptr);
 #elif defined(GMIO_HAVE_STRTOF_FUNC) /* Requires C99 */
diff --git a/src/gmio_core/internal/string_utils.h b/src/gmio_core/internal/string_utils.h
index 9d7dbe4..e42763f 100644
--- a/src/gmio_core/internal/string_utils.h
+++ b/src/gmio_core/internal/string_utils.h
@@ -18,10 +18,6 @@
 
 #include "../global.h"
 
-/*#define GMIO_STRINGUTILS_C_ARRAYS*/
-/*#define GMIO_STRINGUTILS_CTYPE_H*/
-#define GMIO_STRINGUTILS_DIRECT_TESTS
-
 #ifdef GMIO_STRINGUTILS_CTYPE_H
 #  include <ctype.h>
 #endif