diff --git a/CMakeLists.txt b/CMakeLists.txt
index 96d317d..7238f42 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,8 +1,8 @@
-cmake_minimum_required(VERSION 3.27)
+cmake_minimum_required(VERSION 3.18)
 project(project C)
 
-set(CMAKE_C_STANDARD 17)
+set(CMAKE_C_STANDARD 11)
 
-set(CMAKE_C_FLAGS "-Wall -Werror -g -fstack-protector -z noexecstack -z relro -z now -pie -fPIE -Wl,-z,relro,-z,now")
+set(CMAKE_C_FLAGS "-Wall -Werror -g -fstack-protector -fshort-enums -z noexecstack -z relro -z now -pie -fPIE -Wl,-z,relro,-z,now")
 
 add_executable(vuln vuln.c)
diff --git a/vuln.c b/vuln.c
index caaf4c2..8731666 100644
--- a/vuln.c
+++ b/vuln.c
@@ -9,9 +9,9 @@
 
 #define MAX_PROGRAM_LEN 0x1000
 
-typedef enum Opcode : uint8_t { ADD = 0, ADDI = 1, SUB = 2, COPY = 3, LOADI = 4, COUNT_OPCODES } Opcode;
+typedef enum Opcode { ADD = 0, ADDI = 1, SUB = 2, COPY = 3, LOADI = 4, COUNT_OPCODES } Opcode;
 
-typedef enum Register : uint8_t { Adelheid = 0, Berthold = 1, Cornelia = 2, Dora = 3, Engelbert = 4, Friedrich = 5, Giesela = 6, Heinrich = 7, COUNT_REGISTERS } Register;
+typedef enum Register { Adelheid = 0, Berthold = 1, Cornelia = 2, Dora = 3, Engelbert = 4, Friedrich = 5, Giesela = 6, Heinrich = 7, COUNT_REGISTERS } Register;
 
 typedef struct Instruction {
     Opcode opcode;