diff --git a/config.mk b/config.mk
index a5b9fb7..9876f3c 100644
--- a/config.mk
+++ b/config.mk
@@ -7,7 +7,6 @@
 ################################################################################
 
 # EDIT HERE:
-CC:=gcc
 CFLAGS:=-Os -std=c99 -Wall -Wextra -D_ISOC99_SOURCE -MMD -I../lib/include/ -I../lib/source/ -I../tests/include/
 vpath %.c ../lib/source/
 ENABLE_TESTS=true
@@ -27,7 +26,6 @@ else
 CFLAGS += -DDISABLE_TESTS
 endif
 
-export CC
 export CFLAGS
 export VPATH
 export ENABLE_TESTS
diff --git a/lib/source/ctr_prng.c b/lib/source/ctr_prng.c
index cac2cc4..3b1d72b 100644
--- a/lib/source/ctr_prng.c
+++ b/lib/source/ctr_prng.c
@@ -52,13 +52,12 @@
  */
 static void arrInc(uint8_t arr[], unsigned int len)
 {
-	unsigned int i;
 	if (0 != arr) {
-		for (i = len; i > 0U; i--) {
-			if (++arr[i-1] != 0U) {
+		do {
+			if (++arr[len - 1] != 0) {
 				break;
 			}
-		}
+		} while (len--);
 	}
 }