diff --git a/codegen.c b/codegen.c
index c27a3fe..89a09ec 100644
--- a/codegen.c
+++ b/codegen.c
@@ -884,6 +884,13 @@ void codegen_generate_normal_unary(struct node *node, struct history *history) {
           "eax", STACK_FRAME_ELEMENT_TYPE_PUSHED_VALUE, "result_value", 0,
           &(struct stack_frame_data){.dtype = last_dtype});
     }
+  } else if (S_EQ(node->unary.op, "!")) {
+    asm_push("cmp eax, 0");
+    asm_push("sete al");
+    asm_push("movzx eax, al");
+    asm_push_ins_push_with_data(
+        "eax", STACK_FRAME_ELEMENT_TYPE_PUSHED_VALUE, "result_value", 0,
+        &(struct stack_frame_data){.dtype = last_dtype});
   }
 }
 
diff --git a/expressionable.c b/expressionable.c
index 7b130d6..fb224d7 100644
--- a/expressionable.c
+++ b/expressionable.c
@@ -306,7 +306,7 @@ void expressionable_parse_parentheses(struct expressionable *expressionable) {
 
 void expressionable_parse_for_normal_unary(
     struct expressionable *expressionable) {
-  const char *unary_op = expressionable_peek_next(expressionable)->sval;
+  const char *unary_op = expressionable_token_next(expressionable)->sval;
   expressionable_parse(expressionable);
 
   void *unary_operand_node = expressionable_node_pop(expressionable);
diff --git a/preprocessor/preprocessor.c b/preprocessor/preprocessor.c
index ddcfe9f..4965efd 100644
--- a/preprocessor/preprocessor.c
+++ b/preprocessor/preprocessor.c
@@ -1338,6 +1338,24 @@ int preprocessor_evaluate_exp(struct compile_process *compiler,
                                  node->exp.op);
 }
 
+int preprocessor_evaluate_unary(struct compile_process *compiler,
+                                struct preprocessor_node *node) {
+  int res = 0;
+  const char *op = node->unary_node.op;
+  struct preprocessor_node *right_operand = node->unary_node.operand;
+  if (S_EQ(op, "!")) {
+    res = !preprocessor_evaluate(compiler, right_operand);
+  } else if (S_EQ(op, "~")) {
+    res = ~preprocessor_evaluate(compiler, right_operand);
+  } else if (S_EQ(op, "-")) {
+    res = -preprocessor_evaluate(compiler, right_operand);
+  } else {
+    compiler_error(compiler, "unknown unary operator");
+  }
+
+  return res;
+}
+
 int preprocessor_evaluate(struct compile_process *compiler,
                           struct preprocessor_node *root_node) {
   struct preprocessor_node *current = root_node;
@@ -1354,6 +1372,10 @@ int preprocessor_evaluate(struct compile_process *compiler,
   case PREPROCESSOR_EXPRESSION_NODE:
     res = preprocessor_evaluate_exp(compiler, current);
     break;
+
+  case PREPROCESSOR_UNARY_NODE:
+    res = preprocessor_evaluate_unary(compiler, current);
+    break;
   }
 
   return res;
diff --git a/test.c b/test.c
index a6432df..53132f9 100644
--- a/test.c
+++ b/test.c
@@ -1,8 +1,6 @@
-#define TEST_FUNC(s) #s
+#define ABC !1
+#if ABC > 0
+#error "ABC > 0"
+#endif
 
-int printf(const char *format, ...);
-
-int main() {
-  const char *s = TEST_FUNC(Hello World !);
-  printf("%s\n", s);
-}
+int main() { return !0; }