diff --git a/9_Firmware/tests/cross_layer/test_cross_layer_contract.py b/9_Firmware/tests/cross_layer/test_cross_layer_contract.py
index c3b950e..6d103de 100644
--- a/9_Firmware/tests/cross_layer/test_cross_layer_contract.py
+++ b/9_Firmware/tests/cross_layer/test_cross_layer_contract.py
@@ -49,8 +49,8 @@ sys.path.insert(0, str(cp.GUI_DIR))
 # Helpers
 # ===================================================================
 
-IVERILOG = os.environ.get("IVERILOG", "/opt/homebrew/bin/iverilog")
-VVP = os.environ.get("VVP", "/opt/homebrew/bin/vvp")
+IVERILOG = os.environ.get("IVERILOG", "iverilog")
+VVP = os.environ.get("VVP", "vvp")
 CXX = os.environ.get("CXX", "c++")
 
 # Check tool availability for conditional skipping
@@ -61,6 +61,20 @@ _has_cxx = subprocess.run(
     [CXX, "--version"], capture_output=True
 ).returncode == 0
 
+# In CI, missing tools must be a hard failure — never silently skip.
+_in_ci = os.environ.get("GITHUB_ACTIONS") == "true"
+if _in_ci:
+    if not _has_iverilog:
+        raise RuntimeError(
+            "iverilog is required in CI but was not found. "
+            "Ensure 'apt-get install iverilog' ran and IVERILOG/VVP are on PATH."
+        )
+    if not _has_cxx:
+        raise RuntimeError(
+            "C++ compiler is required in CI but was not found. "
+            "Ensure build-essential is installed."
+        )
+
 
 def _parse_hex_results(text: str) -> list[dict[str, str]]:
     """Parse space-separated hex lines from TB output files."""