diff --git a/include/xsk/arc/common/directive.hpp b/include/xsk/arc/common/directive.hpp
index 0f5d72ae..7a675f35 100644
--- a/include/xsk/arc/common/directive.hpp
+++ b/include/xsk/arc/common/directive.hpp
@@ -14,6 +14,7 @@ struct directive
 
     kind type;
     bool skip;
+    bool exec;
 };
 
 } // namespace xsk::arc
diff --git a/include/xsk/gsc/common/directive.hpp b/include/xsk/gsc/common/directive.hpp
index 1535ec37..699f387f 100644
--- a/include/xsk/gsc/common/directive.hpp
+++ b/include/xsk/gsc/common/directive.hpp
@@ -14,6 +14,7 @@ struct directive
 
     kind type;
     bool skip;
+    bool exec;
 };
 
 } // namespace xsk::gsc
diff --git a/src/arc/preprocessor.cpp b/src/arc/preprocessor.cpp
index 394b9174..9db17a27 100644
--- a/src/arc/preprocessor.cpp
+++ b/src/arc/preprocessor.cpp
@@ -258,7 +258,7 @@ auto preprocessor::read_directive(token& tok) -> void
 auto preprocessor::read_directive_if(token&) -> void
 {
     auto skip = !evaluate();
-    indents_.push({ directive::IF, skip });
+    indents_.push({ directive::IF, skip, !skip });
     skip_ += skip ? 1 : 0;
 }
 
@@ -283,7 +283,7 @@ auto preprocessor::read_directive_ifdef(token&) -> void
         skip = !defines_.contains(name);
     }
 
-    indents_.push({ directive::IFDEF, skip });
+    indents_.push({ directive::IFDEF, skip, !skip });
     skip_ += skip ? 1 : 0;
 }
 
@@ -308,7 +308,7 @@ auto preprocessor::read_directive_ifndef(token&) -> void
         skip = defines_.contains(name);
     }
 
-    indents_.push({ directive::IFNDEF, skip });
+    indents_.push({ directive::IFNDEF, skip, !skip });
     skip_ += skip ? 1 : 0;
 }
 
@@ -328,8 +328,8 @@ auto preprocessor::read_directive_elif(token& tok) -> void
         throw ppr_error(tok.pos, "#elif after #else");
     }
 
-    auto skip = !evaluate();
-    indents_.push({ directive::ELIF, skip });
+    auto skip = !evaluate() || dir.exec;
+    indents_.push({ directive::ELIF, skip, !skip || dir.exec });
     skip_ += skip ? 1 : 0;
 }
 
@@ -365,10 +365,10 @@ auto preprocessor::read_directive_elifdef(token& tok) -> void
         next = read_token();
         expect(next, token::NEWLINE);
 
-        skip = !defines_.contains(name);
+        skip = !defines_.contains(name) || dir.exec;
     }
 
-    indents_.push({ directive::ELIFDEF, skip });
+    indents_.push({ directive::ELIFDEF, skip, !skip || dir.exec });
     skip_ += skip ? 1 : 0;
 }
 
@@ -404,10 +404,10 @@ auto preprocessor::read_directive_elifndef(token& tok) -> void
         next = read_token();
         expect(next, token::NEWLINE);
 
-        skip = defines_.contains(name);
+        skip = defines_.contains(name) || dir.exec;
     }
 
-    indents_.push({ directive::ELIFNDEF, skip });
+    indents_.push({ directive::ELIFNDEF, skip, !skip || dir.exec });
     skip_ += skip ? 1 : 0;
 }
 
@@ -430,8 +430,8 @@ auto preprocessor::read_directive_else(token& tok) -> void
         throw ppr_error(tok.pos, "#else after #else");
     }
 
-    auto skip = !dir.skip;
-    indents_.push({ directive::ELSE, skip });
+    auto skip = dir.exec;
+    indents_.push({ directive::ELSE, skip, dir.exec });
     skip_ += skip ? 1 : 0;
 }
 
@@ -987,7 +987,21 @@ auto preprocessor::evaluate() -> bool
         }
         else if (tok.type == token::NAME)
         {
-            if (tok.data == "defined")
+            if (tok.data == "true")
+            {
+                last_def = false;
+                last_paren = false;
+                tok.type = token::TRUE;
+                expr_.push_back(std::move(tok));
+            }
+            else if (tok.data == "false")
+            {
+                last_def = false;
+                last_paren = false;
+                tok.type = token::FALSE;
+                expr_.push_back(std::move(tok));
+            }
+            else if (tok.data == "defined")
             {
                 last_def = true;
                 tok.type = token::DEFINED;
diff --git a/src/gsc/preprocessor.cpp b/src/gsc/preprocessor.cpp
index abb09040..d084367e 100644
--- a/src/gsc/preprocessor.cpp
+++ b/src/gsc/preprocessor.cpp
@@ -258,7 +258,7 @@ auto preprocessor::read_directive(token& tok) -> void
 auto preprocessor::read_directive_if(token&) -> void
 {
     auto skip = !evaluate();
-    indents_.push({ directive::IF, skip });
+    indents_.push({ directive::IF, skip, !skip });
     skip_ += skip ? 1 : 0;
 }
 
@@ -283,7 +283,7 @@ auto preprocessor::read_directive_ifdef(token&) -> void
         skip = !defines_.contains(name);
     }
 
-    indents_.push({ directive::IFDEF, skip });
+    indents_.push({ directive::IFDEF, skip, !skip });
     skip_ += skip ? 1 : 0;
 }
 
@@ -308,7 +308,7 @@ auto preprocessor::read_directive_ifndef(token&) -> void
         skip = defines_.contains(name);
     }
 
-    indents_.push({ directive::IFNDEF, skip });
+    indents_.push({ directive::IFNDEF, skip, !skip });
     skip_ += skip ? 1 : 0;
 }
 
@@ -328,8 +328,8 @@ auto preprocessor::read_directive_elif(token& tok) -> void
         throw ppr_error(tok.pos, "#elif after #else");
     }
 
-    auto skip = !evaluate();
-    indents_.push({ directive::ELIF, skip });
+    auto skip = !evaluate() || dir.exec;
+    indents_.push({ directive::ELIF, skip, !skip || dir.exec });
     skip_ += skip ? 1 : 0;
 }
 
@@ -365,10 +365,10 @@ auto preprocessor::read_directive_elifdef(token& tok) -> void
         next = read_token();
         expect(next, token::NEWLINE);
 
-        skip = !defines_.contains(name);
+        skip = !defines_.contains(name) || dir.exec;
     }
 
-    indents_.push({ directive::ELIFDEF, skip });
+    indents_.push({ directive::ELIFDEF, skip, !skip || dir.exec });
     skip_ += skip ? 1 : 0;
 }
 
@@ -404,10 +404,10 @@ auto preprocessor::read_directive_elifndef(token& tok) -> void
         next = read_token();
         expect(next, token::NEWLINE);
 
-        skip = defines_.contains(name);
+        skip = defines_.contains(name) || dir.exec;
     }
 
-    indents_.push({ directive::ELIFNDEF, skip });
+    indents_.push({ directive::ELIFNDEF, skip, !skip || dir.exec });
     skip_ += skip ? 1 : 0;
 }
 
@@ -430,8 +430,8 @@ auto preprocessor::read_directive_else(token& tok) -> void
         throw ppr_error(tok.pos, "#else after #else");
     }
 
-    auto skip = !dir.skip;
-    indents_.push({ directive::ELSE, skip });
+    auto skip = dir.exec;
+    indents_.push({ directive::ELSE, skip, dir.exec });
     skip_ += skip ? 1 : 0;
 }
 
@@ -970,7 +970,21 @@ auto preprocessor::evaluate() -> bool
         }
         else if (tok.type == token::NAME)
         {
-            if (tok.data == "defined")
+            if (tok.data == "true")
+            {
+                last_def = false;
+                last_paren = false;
+                tok.type = token::TRUE;
+                expr_.push_back(std::move(tok));
+            }
+            else if (tok.data == "false")
+            {
+                last_def = false;
+                last_paren = false;
+                tok.type = token::FALSE;
+                expr_.push_back(std::move(tok));
+            }
+            else if (tok.data == "defined")
             {
                 last_def = true;
                 tok.type = token::DEFINED;
@@ -1314,16 +1328,16 @@ auto preprocessor::eval_expr_primary() -> i32
 {
     if (eval_match(token::TRUE))
         return 1;
-    
+
     if (eval_match(token::FALSE))
         return 0;
-    
+
     if (eval_match(token::FLT))
         return static_cast<i32>(std::stof(eval_prev().data));
-    
+
     if (eval_match(token::INT))
         return static_cast<i32>(std::stoi(eval_prev().data));
-    
+
     if (eval_match(token::LPAREN))
     {
         auto val = eval_expr();