diff --git a/CMakeLists.txt b/CMakeLists.txt
index 12c6a44..72975ef 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.27)
+cmake_minimum_required(VERSION 3.20)
 project(psil)
 
 if (SANITIZE STREQUAL "YES")
@@ -18,7 +18,7 @@ if (NOT CMAKE_BUILD_TYPE STREQUAL "Debug")
     add_link_options(-O3)
 endif ()
 
-set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_STANDARD 17)
 
 add_subdirectory(src)
 
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index b7abc67..856483f 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,4 +1,4 @@
-set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 add_subdirectory(vm)
diff --git a/src/vm/CMakeLists.txt b/src/vm/CMakeLists.txt
index b7a5177..f0c3fbb 100644
--- a/src/vm/CMakeLists.txt
+++ b/src/vm/CMakeLists.txt
@@ -1,4 +1,4 @@
-set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 add_library(vm src/VM.cpp src/Cell.cpp
diff --git a/src/vm/include/Cell.h b/src/vm/include/Cell.h
index d3baa57..f86e2ed 100644
--- a/src/vm/include/Cell.h
+++ b/src/vm/include/Cell.h
@@ -11,6 +11,8 @@
 #include <sstream>
 #include <string>
 #include <utility>
+#include <atomic>
+
 enum class CellType {
     NUMATOM,
     STRATOM,
diff --git a/src/vm/include/Compiler.h b/src/vm/include/Compiler.h
index e071850..d272163 100644
--- a/src/vm/include/Compiler.h
+++ b/src/vm/include/Compiler.h
@@ -7,6 +7,7 @@
 
 
 #include "Handle.h"
+
 class Compiler {
 public:
     static Handle compile(Handle src, Handle fake_env = nullptr, Handle suffix = nullptr);
diff --git a/src/vm/include/Handle.h b/src/vm/include/Handle.h
index 2504850..34a3669 100644
--- a/src/vm/include/Handle.h
+++ b/src/vm/include/Handle.h
@@ -29,10 +29,6 @@ public:
                 return dynamic_cast<NumAtomCell &>(*_target)._val == dynamic_cast<NumAtomCell &>(*rhs._target)._val;
             } else if (_target->_type == CellType::STRATOM) {
                 return dynamic_cast<StrAtomCell &>(*_target)._val == dynamic_cast<StrAtomCell &>(*rhs._target)._val;
-            } else if (_target->_type == CellType::CONS) {
-                // This is questionable
-                return dynamic_cast<ConsCell &>(*_target)._car == dynamic_cast<ConsCell &>(*rhs._target)._car &&
-                       dynamic_cast<ConsCell &>(*_target)._cdr == dynamic_cast<ConsCell &>(*rhs._target)._cdr;
             }
         }
         return false;
diff --git a/src/vm/include/MemoryContext.h b/src/vm/include/MemoryContext.h
index 393b94e..7a9ea06 100644
--- a/src/vm/include/MemoryContext.h
+++ b/src/vm/include/MemoryContext.h
@@ -14,6 +14,7 @@
 #include <queue>
 #include <set>
 #include <thread>
+#include <functional>
 
 #include "Cell.h"
 #include "Handle.h"
diff --git a/src/vm/src/Compiler.cpp b/src/vm/src/Compiler.cpp
index b046af2..76b0aa6 100644
--- a/src/vm/src/Compiler.cpp
+++ b/src/vm/src/Compiler.cpp
@@ -5,13 +5,14 @@
 #include "Compiler.h"
 
 #include <string>
+#include <functional>
 
 Handle Compiler::compile(Handle src, Handle fake_env, Handle suffix) {
     Handle out;
 
     std::function<Handle(Handle)> compileArgsRaw = [&](Handle args) {
         Handle out;
-        while (args != nullptr) {
+        while (!args.null()) {
             out.splice(compile(args.car(), fake_env));
             args = args.cdr();
         }
@@ -21,7 +22,7 @@ Handle Compiler::compile(Handle src, Handle fake_env, Handle suffix) {
     std::function<Handle(Handle, Handle)> compileArgsList = [&](Handle args, Handle env) {
         Handle out;
         out.append(Handle("NIL"));
-        while (args != nullptr) {
+        while (!args.null()) {
             out.splice(compile(args.car(), env));
             out.append(Handle("CONS"));
             args = args.cdr();
@@ -74,7 +75,7 @@ Handle Compiler::compile(Handle src, Handle fake_env, Handle suffix) {
 
                 Handle body = cdr.cdr().car();
 
-                while (definitions != nullptr) {
+                while (!definitions.null()) {
                     argBody.emplace_back(definitions.car().car(), definitions.car().cdr().car());
                     argNames.append(definitions.car().car());
                     argBodies.append(definitions.car().cdr().car());
@@ -116,11 +117,11 @@ Handle Compiler::findIndex(Handle symbol, Handle env) {
 
     Handle curFrame = env;
 
-    while (curFrame != nullptr) {
+    while (!curFrame.null()) {
         int64_t arg = 1;
         Handle curArg = curFrame.car();
 
-        while (curArg != nullptr) {
+        while (!curArg.null()) {
             if (curArg.car() == symbol) return Handle::cons(frame, arg);
             curArg = curArg.cdr();
             arg++;
diff --git a/src/vm/src/Parser.cpp b/src/vm/src/Parser.cpp
index f092892..91fe511 100644
--- a/src/vm/src/Parser.cpp
+++ b/src/vm/src/Parser.cpp
@@ -4,7 +4,6 @@
 
 #include "Parser.h"
 
-#include <format>
 #include <ranges>
 #include <stack>
 
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 26381c9..a36b033 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -1,4 +1,4 @@
-set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 include(FetchContent)