diff --git a/src/config.h b/src/config.h
index 42ee08218..6ecc96548 100644
--- a/src/config.h
+++ b/src/config.h
@@ -96,14 +96,34 @@
 /**
  * Use 32-bit/64-bit float for ecma-numbers
  */
-#define CONFIG_ECMA_NUMBER_FLOAT32
-// #define CONFIG_ECMA_NUMBER_FLOAT64
+#define CONFIG_ECMA_NUMBER_FLOAT32 (1u) /* 32-bit float */
+#define CONFIG_ECMA_NUMBER_FLOAT64 (2u) /* 64-bit float */
+
+#ifndef CONFIG_ECMA_NUMBER_TYPE
+# define CONFIG_ECMA_NUMBER_TYPE CONFIG_ECMA_NUMBER_FLOAT32
+#else /* !CONFIG_ECMA_NUMBER_TYPE */
+# if (CONFIG_ECMA_NUMBER_TYPE != CONFIG_ECMA_NUMBER_FLOAT32 \
+      && CONFIG_ECMA_NUMBER_TYPE != CONFIG_ECMA_NUMBER_FLOAT64)
+#  error "ECMA-number storage is configured incorrectly"
+# endif /* CONFIG_ECMA_NUMBER_TYPE != CONFIG_ECMA_NUMBER_FLOAT32
+           && CONFIG_ECMA_NUMBER_TYPE != CONFIG_ECMA_NUMBER_FLOAT64 */
+#endif /* CONFIG_ECMA_NUMBER_TYPE */
 
 /**
- * Use ASCII/UTF-16 representation for ecma-characters
+ * Representation for ecma-characters
  */
-#define CONFIG_ECMA_CHAR_ASCII
-// #define CONFIG_ECMA_CHAR_UTF16
+#define CONFIG_ECMA_CHAR_ASCII (1) /* ASCII */
+#define CONFIG_ECMA_CHAR_UTF16 (2) /* UTF-16 */
+
+#ifndef CONFIG_ECMA_CHAR_ENCODING
+# define CONFIG_ECMA_CHAR_ENCODING CONFIG_ECMA_CHAR_ASCII
+#else /* !CONFIG_ECMA_CHAR_ENCODING */
+# if (CONFIG_ECMA_CHAR_ENCODING != CONFIG_ECMA_CHAR_ASCII \
+      && CONFIG_ECMA_CHAR_ENCODING != CONFIG_ECMA_CHAR_UTF16)
+#  error "ECMA-char encoding is configured incorrectly"
+# endif /* CONFIG_ECMA_CHAR_ENCODING != CONFIG_ECMA_CHAR_ASCII
+           && CONFIG_ECMA_CHAR_ENCODING != CONFIG_ECMA_CHAR_UTF16 */
+#endif /* CONFIG_ECMA_CHAR_ENCODING */
 
 /**
  * Enable ecma-exception support
diff --git a/src/libcoreint/opcodes-native-call.c b/src/libcoreint/opcodes-native-call.c
index 7ee07cc43..73e3c08c9 100644
--- a/src/libcoreint/opcodes-native-call.c
+++ b/src/libcoreint/opcodes-native-call.c
@@ -138,13 +138,11 @@ opfunc_native_call (opcode_t opdata, /**< operation data */
 
         ecma_string_to_zt_string (str_p, zt_str_p, zt_str_size);
 
-#if defined (CONFIG_ECMA_CHAR_ASCII)
+#if CONFIG_ECMA_CHAR_ENCODING == CONFIG_ECMA_CHAR_ASCII
         __printf ("%s\n", (char*) zt_str_p);
-#elif defined (CONFIG_ECMA_CHAR_UTF16)
+#elif CONFIG_ECMA_CHAR_ENCODING == CONFIG_ECMA_CHAR_UTF16
         JERRY_UNIMPLEMENTED ();
-#else /* !CONFIG_ECMA_CHAR_ASCII && !CONFIG_ECMA_CHAR_UTF16 */
-# error "!CONFIG_ECMA_CHAR_ASCII && !CONFIG_ECMA_CHAR_UTF16"
-#endif /* !CONFIG_ECMA_CHAR_ASCII && !CONFIG_ECMA_CHAR_UTF16 */
+#endif /* CONFIG_ECMA_CHAR_ENCODING == CONFIG_ECMA_CHAR_UTF16 */
 
         mem_heap_free_block (zt_str_p);
 
diff --git a/src/libecmabuiltins/ecma-builtin-string-object.c b/src/libecmabuiltins/ecma-builtin-string-object.c
index 8da6c24aa..5552cf180 100644
--- a/src/libecmabuiltins/ecma-builtin-string-object.c
+++ b/src/libecmabuiltins/ecma-builtin-string-object.c
@@ -108,7 +108,7 @@ ecma_builtin_string_object_from_char_code (ecma_value_t args[], /**< arguments l
     uint32_t uint32_char_code = ecma_number_to_uint32 (*arg_num_p);
     uint16_t uint16_char_code = (uint16_t) uint32_char_code;
 
-#if defined (CONFIG_ECMA_CHAR_ASCII)
+#if CONFIG_ECMA_CHAR_ENCODING == CONFIG_ECMA_CHAR_ASCII
     if ((uint16_char_code >> JERRY_BITSINBYTE) != 0)
     {
       ret_value = ecma_make_throw_obj_completion_value (ecma_new_standard_error (ECMA_ERROR_TYPE));
@@ -117,11 +117,9 @@ ecma_builtin_string_object_from_char_code (ecma_value_t args[], /**< arguments l
     {
       ret_zt_str_p [arg_index] = (ecma_char_t) uint16_char_code;
     }
-#elif defined (CONFIG_ECMA_CHAR_UTF16)
+#elif CONFIG_ECMA_CHAR_ENCODING == CONFIG_ECMA_CHAR_UTF16
     ret_zt_str_p [arg_index] = (ecma_char_t) uint16_char_code;
-#else /* !CONFIG_ECMA_CHAR_ASCII && !CONFIG_ECMA_CHAR_UTF16 */
-# error "!CONFIG_ECMA_CHAR_ASCII && !CONFIG_ECMA_CHAR_UTF16"
-#endif /* !CONFIG_ECMA_CHAR_ASCII && !CONFIG_ECMA_CHAR_UTF16 */
+#endif /* CONFIG_ECMA_CHAR_ENCODING == CONFIG_ECMA_CHAR_UTF16 */
 
     ECMA_FINALIZE (arg_num_value);
 
diff --git a/src/libecmaobjects/ecma-globals.h b/src/libecmaobjects/ecma-globals.h
index c9a4e8a47..1c967b29a 100644
--- a/src/libecmaobjects/ecma-globals.h
+++ b/src/libecmaobjects/ecma-globals.h
@@ -506,21 +506,19 @@ typedef struct
   ecma_property_configurable_value_t configurable;
 } ecma_property_descriptor_t;
 
-#ifdef CONFIG_ECMA_CHAR_ASCII
+#if CONFIG_ECMA_CHAR_ENCODING == CONFIG_ECMA_CHAR_ASCII
 /**
  * Description of an ecma-character
  */
 typedef uint8_t ecma_char_t;
-#elif defined (CONFIG_ECMA_CHAR_UTF16)
+#elif CONFIG_ECMA_CHAR_ENCODING == CONFIG_ECMA_CHAR_UTF16
 /**
  * Description of an ecma-character
  */
 typedef uint16_t ecma_char_t;
-#else /* !CONFIG_ECMA_CHAR_ASCII && !CONFIG_ECMA_CHAR_UTF16 */
-# error "!CONFIG_ECMA_CHAR_ASCII && !CONFIG_ECMA_CHAR_UTF16"
-#endif /* !CONFIG_ECMA_CHAR_ASCII && !CONFIG_ECMA_CHAR_UTF16 */
+#endif /* CONFIG_ECMA_CHAR_ENCODING == CONFIG_ECMA_CHAR_UTF16 */
 
-#ifdef CONFIG_ECMA_NUMBER_FLOAT32
+#if CONFIG_ECMA_NUMBER_TYPE == CONFIG_ECMA_NUMBER_FLOAT32
 /**
  * Description of an ecma-number
  */
@@ -530,7 +528,7 @@ typedef float ecma_number_t;
  * Maximum number of significant digits that ecma-number can store
  */
 #define ECMA_NUMBER_MAX_DIGITS  (10u)
-#elif defined (CONFIG_ECMA_NUMBER_FLOAT64)
+#elif CONFIG_ECMA_NUMBER_TYPE == CONFIG_ECMA_NUMBER_FLOAT64
 /**
  * Description of an ecma-number
  */
@@ -540,9 +538,7 @@ typedef double ecma_number_t;
  * Maximum number of significant digits that ecma-number can store
  */
 #define ECMA_NUMBER_MAX_DIGITS  (18u)
-#else /* !CONFIG_ECMA_NUMBER_FLOAT32 && !CONFIG_ECMA_NUMBER_FLOAT64 */
-#error "!CONFIG_ECMA_NUMBER_FLOAT32 && !CONFIG_ECMA_NUMBER_FLOAT64"
-#endif /* !CONFIG_ECMA_NUMBER_FLOAT32 && !CONFIG_ECMA_NUMBER_FLOAT64 */
+#endif /* CONFIG_ECMA_NUMBER_TYPE == CONFIG_ECMA_NUMBER_FLOAT64 */
 
 /**
  * Value '0' of ecma_number_t
@@ -567,10 +563,10 @@ typedef double ecma_number_t;
 /**
  * Minimum positive and maximum value of ecma-number
  */
-#ifdef CONFIG_ECMA_NUMBER_FLOAT32
+#if CONFIG_ECMA_NUMBER_TYPE == CONFIG_ECMA_NUMBER_FLOAT32
 # define ECMA_NUMBER_MIN_VALUE (FLT_MIN)
 # define ECMA_NUMBER_MAX_VALUE (FLT_MAX)
-#elif defined (CONFIG_ECMA_NUMBER_FLOAT64)
+#elif CONFIG_ECMA_NUMBER_TYPE == CONFIG_ECMA_NUMBER_FLOAT64
 /**
  * Number.MAX_VALUE
  *
@@ -583,10 +579,7 @@ typedef double ecma_number_t;
  * See also: ECMA_262 v5, 15.7.3.3
  */
 # define ECMA_NUMBER_MIN_VALUE ((ecma_number_t)5e-324)
-#else /* !CONFIG_ECMA_NUMBER_FLOAT32 && !CONFIG_ECMA_NUMBER_FLOAT64 */
-# error "!CONFIG_ECMA_NUMBER_FLOAT32 && !CONFIG_ECMA_NUMBER_FLOAT64"
-#endif /* !CONFIG_ECMA_NUMBER_FLOAT32 && !CONFIG_ECMA_NUMBER_FLOAT64 */
-
+#endif /* CONFIG_ECMA_NUMBER_TYPE == CONFIG_ECMA_NUMBER_FLOAT64 */
 
 /**
  * Euler number
diff --git a/src/libecmaobjects/ecma-helpers-conversion.c b/src/libecmaobjects/ecma-helpers-conversion.c
index 1e2b8a8d6..7ce0251ee 100644
--- a/src/libecmaobjects/ecma-helpers-conversion.c
+++ b/src/libecmaobjects/ecma-helpers-conversion.c
@@ -801,15 +801,13 @@ ecma_number_to_zt_string (ecma_number_t num, /**< ecma-number */
     else
     {
       // 5.
-#ifdef CONFIG_ECMA_NUMBER_FLOAT32
+#if CONFIG_ECMA_NUMBER_TYPE == CONFIG_ECMA_NUMBER_FLOAT32
 #define LL_T uint32_t
 #define LL_MAX_DIGITS 10
-#elif defined (CONFIG_ECMA_NUMBER_FLOAT64)
+#elif CONFIG_ECMA_NUMBER_TYPE == CONFIG_ECMA_NUMBER_FLOAT64
 #define LL_T uint64_t
 #define LL_MAX_DIGITS 18
-#else /* !CONFIG_ECMA_NUMBER_FLOAT32 && !CONFIG_ECMA_NUMBER_FLOAT64 */
-# error "!CONFIG_ECMA_NUMBER_FLOAT32 && !CONFIG_ECMA_NUMBER_FLOAT64"
-#endif /* !CONFIG_ECMA_NUMBER_FLOAT32 && !CONFIG_ECMA_NUMBER_FLOAT64 */
+#endif /* CONFIG_ECMA_NUMBER_TYPE == CONFIG_ECMA_NUMBER_FLOAT64 */
 
       uint32_t num_uint32 = ecma_number_to_uint32 (num);
       if (ecma_uint32_to_number (num_uint32) == num)
diff --git a/src/libecmaobjects/ecma-helpers-number.c b/src/libecmaobjects/ecma-helpers-number.c
index efd78d8bd..d9395cea1 100644
--- a/src/libecmaobjects/ecma-helpers-number.c
+++ b/src/libecmaobjects/ecma-helpers-number.c
@@ -23,7 +23,7 @@
 #include "ecma-globals.h"
 #include "ecma-helpers.h"
 
-#ifdef CONFIG_ECMA_NUMBER_FLOAT32
+#if CONFIG_ECMA_NUMBER_TYPE == CONFIG_ECMA_NUMBER_FLOAT32
 JERRY_STATIC_ASSERT (sizeof (ecma_number_t) == sizeof (uint32_t));
 
 /**
@@ -80,7 +80,7 @@ const int32_t ecma_number_exponent_bias = 127;
  * Relative precision used in calculation with ecma-numbers
  */
 const ecma_number_t ecma_number_relative_eps = 1.0e-10f;
-#elif defined (CONFIG_ECMA_NUMBER_FLOAT64)
+#elif CONFIG_ECMA_NUMBER_TYPE == CONFIG_ECMA_NUMBER_FLOAT64
 JERRY_STATIC_ASSERT (sizeof (ecma_number_t) == sizeof (uint64_t));
 
 /**
@@ -137,9 +137,7 @@ const int32_t ecma_number_exponent_bias = 1023;
  * Relative precision used in calculation with ecma-numbers
  */
 const ecma_number_t ecma_number_relative_eps = 1.0e-16;
-#else /* !CONFIG_ECMA_NUMBER_FLOAT32 && !CONFIG_ECMA_NUMBER_FLOAT64 */
-# error "!CONFIG_ECMA_NUMBER_FLOAT32 && !CONFIG_ECMA_NUMBER_FLOAT64"
-#endif /* !CONFIG_ECMA_NUMBER_FLOAT32 && !CONFIG_ECMA_NUMBER_FLOAT64 */
+#endif /* CONFIG_ECMA_NUMBER_TYPE == CONFIG_ECMA_NUMBER_FLOAT64 */
 
 /**
  * Get fraction of number
diff --git a/src/libecmaobjects/ecma-helpers-string.c b/src/libecmaobjects/ecma-helpers-string.c
index f579da9b7..d48f8627a 100644
--- a/src/libecmaobjects/ecma-helpers-string.c
+++ b/src/libecmaobjects/ecma-helpers-string.c
@@ -1088,7 +1088,7 @@ ecma_compare_zt_strings_relational (const ecma_char_t *string1_p, /**< zero-term
   while (*iter_1_p != ECMA_CHAR_NULL
          && *iter_2_p != ECMA_CHAR_NULL)
   {
-#ifdef CONFIG_ECMA_CHAR_ASCII
+#if CONFIG_ECMA_CHAR_ENCODING == CONFIG_ECMA_CHAR_ASCII
     const ecma_char_t chr_1 = *iter_1_p++;
     const ecma_char_t chr_2 = *iter_2_p++;
 
@@ -1100,7 +1100,7 @@ ecma_compare_zt_strings_relational (const ecma_char_t *string1_p, /**< zero-term
     {
       return false;
     }
-#elif defined (CONFIG_ECMA_CHAR_UTF16)
+#elif CONFIG_ECMA_CHAR_ENCODING == CONFIG_ECMA_CHAR_UTF16
     const ecma_char_t first_in_pair_range_begin = 0xD800;
     const ecma_char_t first_in_pair_range_end = 0xDBFF;
     const ecma_char_t second_in_pair_range_begin = 0xDC00;
@@ -1176,9 +1176,7 @@ ecma_compare_zt_strings_relational (const ecma_char_t *string1_p, /**< zero-term
         return false;
       }
     }
-#else /* !CONFIG_ECMA_CHAR_ASCII && !CONFIG_ECMA_CHAR_UTF16 */
-# error "!CONFIG_ECMA_CHAR_ASCII && !CONFIG_ECMA_CHAR_UTF16"
-#endif /* !CONFIG_ECMA_CHAR_ASCII && !CONFIG_ECMA_CHAR_UTF16 */
+#endif /* CONFIG_ECMA_CHAR_ENCODING == CONFIG_ECMA_CHAR_UTF16 */
   }
 
   return (*iter_1_p == ECMA_CHAR_NULL