diff --git a/library/aes.c b/library/aes.c
index 0a7b26c..f1a5a44 100644
--- a/library/aes.c
+++ b/library/aes.c
@@ -360,7 +360,7 @@
 /*
  * Round constants
  */
-static const uint32_t RCON[10] =
+static const uint32_t round_constants[10] =
 {
     0x00000001, 0x00000002, 0x00000004, 0x00000008,
     0x00000010, 0x00000020, 0x00000040, 0x00000080,
@@ -407,7 +407,7 @@
 /*
  * Round constants
  */
-static uint32_t RCON[10];
+static uint32_t round_constants[10];
 
 /*
  * Tables generation code
@@ -438,7 +438,7 @@
      * calculate the round constants
      */
     for (i = 0, x = 1; i < 10; i++) {
-        RCON[i] = x;
+        round_constants[i] = x;
         x = XTIME(x);
     }
 
@@ -666,7 +666,7 @@
         case 10:
 
             for (unsigned int i = 0; i < 10; i++, RK += 4) {
-                RK[4]  = RK[0] ^ RCON[i] ^
+                RK[4]  = RK[0] ^ round_constants[i] ^
                          ((uint32_t) FSb[MBEDTLS_BYTE_1(RK[3])]) ^
                          ((uint32_t) FSb[MBEDTLS_BYTE_2(RK[3])] <<  8) ^
                          ((uint32_t) FSb[MBEDTLS_BYTE_3(RK[3])] << 16) ^
@@ -682,7 +682,7 @@
         case 12:
 
             for (unsigned int i = 0; i < 8; i++, RK += 6) {
-                RK[6]  = RK[0] ^ RCON[i] ^
+                RK[6]  = RK[0] ^ round_constants[i] ^
                          ((uint32_t) FSb[MBEDTLS_BYTE_1(RK[5])]) ^
                          ((uint32_t) FSb[MBEDTLS_BYTE_2(RK[5])] <<  8) ^
                          ((uint32_t) FSb[MBEDTLS_BYTE_3(RK[5])] << 16) ^
@@ -699,7 +699,7 @@
         case 14:
 
             for (unsigned int i = 0; i < 7; i++, RK += 8) {
-                RK[8]  = RK[0] ^ RCON[i] ^
+                RK[8]  = RK[0] ^ round_constants[i] ^
                          ((uint32_t) FSb[MBEDTLS_BYTE_1(RK[7])]) ^
                          ((uint32_t) FSb[MBEDTLS_BYTE_2(RK[7])] <<  8) ^
                          ((uint32_t) FSb[MBEDTLS_BYTE_3(RK[7])] << 16) ^