diff --git a/tools/shuriken.py b/tools/shuriken.py
index e5a1943..f65d5be 100755
--- a/tools/shuriken.py
+++ b/tools/shuriken.py
@@ -10,7 +10,6 @@
 ############################################
 
 import argparse
-import copy
 import json
 import shlex
 import subprocess
@@ -18,7 +17,7 @@ import sys
 from collections import namedtuple
 from dataclasses import asdict, dataclass, field
 from pathlib import Path
-from typing import Any
+from typing import Any, Self
 
 import yaml
 
@@ -60,6 +59,38 @@ class TargetConfig:
         return f"{self.linker_args or ''} {self.linker_args_extra or ''}".strip()
 
 
+@dataclass(kw_only=True)
+class MergedTargetConfig(TargetConfig):
+    cpp_compiler: str = ''
+    cpp_standard: str = ''
+    cpp_flags: str = ''
+    cpp_flags_extra: str = ''
+
+    linker_flags: str = ''
+    linker_flags_extra: str = ''
+    linker_args: str = ''
+    linker_args_extra: str = ''
+
+    output_file: str = ''
+    run_command: str = ''
+
+    @classmethod
+    def create_from(cls, target_defaults: TargetConfig, target_config: TargetConfig) -> Self:
+        merged_config = cls()
+        merged_config.update(asdict(target_defaults))
+        merged_config.update(asdict(target_config))
+        return merged_config
+
+    def validate(self) -> None:
+        # Validate that all required fields are set
+        if not self.cpp_compiler:
+            raise ConfigValidationException('cpp_compiler must be set')
+        if not self.cpp_standard:
+            raise ConfigValidationException('cpp_standard must be set')
+        if not self.output_file:
+            raise ConfigValidationException('output_file must be set')
+
+
 @dataclass(kw_only=True)
 class ShurikenConfig:
     __path_fields = ['source_dir', 'build_dir']
@@ -72,9 +103,6 @@ class ShurikenConfig:
     defaults: TargetConfig = field(default_factory=lambda: TargetConfig(
         cpp_compiler='clang++',
         cpp_standard='c++20',
-        cpp_flags='',
-        linker_flags='',
-        linker_args='',
     ))
 
     enable_import_std: bool = False
@@ -82,6 +110,9 @@ class ShurikenConfig:
     default_target: str = ''
     targets: dict[str, TargetConfig] = field(default_factory=dict)
 
+    # Merged target configs, generated from defaults and targets
+    _merged_target_configs = {}
+
     def update(self, data: dict) -> None:
         for key, value in data.items():
             # Ignore unknown config keys
@@ -116,6 +147,10 @@ class ShurikenConfig:
             else:
                 setattr(self, key, str(value))
 
+        # Generate merged target configs (we generate all of them so that we can validate the full config)
+        for target_name, target_config in self.targets.items():
+            self._merged_target_configs[target_name] = MergedTargetConfig.create_from(self.defaults, target_config)
+
     def update_from_yaml(self, file_path: Path) -> None:
         with file_path.open('r') as file:
             self.update(yaml.safe_load(file))
@@ -137,23 +172,18 @@ class ShurikenConfig:
             raise ConfigValidationException('default_target is not defined in targets')
 
         # Validate individual build targets
-        for target_name, target_config in self.targets.items():
-            if not target_config.cpp_compiler and not self.defaults.cpp_compiler:
-                raise ConfigValidationException(f'Target "{target_name}": cpp_compiler must be set')
-            if not target_config.cpp_standard and not self.defaults.cpp_standard:
-                raise ConfigValidationException(f'Target "{target_name}": cpp_standard must be set')
-            if not target_config.output_file and not self.defaults.output_file:
-                raise ConfigValidationException(f'Target "{target_name}": output_file must be set')
+        for target_name, merged_target_config in self._merged_target_configs.items():
+            try:
+                merged_target_config.validate()
+            except ConfigValidationException as exc:
+                raise ConfigValidationException(f'Target "{target_name}": {str(exc)}')
 
     def get_ninja_file_path(self, target: str) -> Path:
         return self.build_dir / f'build.{target}.ninja'
 
-    def get_merged_target_config(self, target: str) -> TargetConfig:
+    def get_merged_target_config(self, target: str) -> MergedTargetConfig:
         assert target in self.targets, f'Target "{target}" not defined!'
-
-        merged_config = copy.deepcopy(self.defaults)
-        merged_config.update(asdict(self.targets[target]))
-        return merged_config
+        return self._merged_target_configs[target]
 
 
 class ShurikenArgumentParser: