diff --git a/src/crypt.c b/src/crypt.c
index f593fca..9d269c7 100644
--- a/src/crypt.c
+++ b/src/crypt.c
@@ -38,7 +38,7 @@ void caesar_encrypt(char* str, int size, int key)
 		if (str[i] != ' ')
 		{
 			bool upper = isupper(str[i]);
-			str[i] += key - (upper ? 65 : 97);
+			str[i] += (char)key - (upper ? 65 : 97);
 			str[i] %= 26;
 			str[i] += (upper ? 65 : 97);
 		}
@@ -51,8 +51,8 @@ void caesar_decrypt(char* str, int size, int key)
 		if (str[i] != ' ')
 		{
 			bool upper = isupper(str[i]);
-			str[i] = str[i] - key - (upper ? 65 : 97);
-			str[i] = mod(str[i], 26);
+			str[i] = str[i] - (char)key - (upper ? 65 : 97);
+			str[i] = (char)mod(str[i], 26);
 			str[i] += (upper ? 65 : 97);
 		}
 }