diff --git a/obliteratus/device.py b/obliteratus/device.py
index 34fc572..6b87739 100644
--- a/obliteratus/device.py
+++ b/obliteratus/device.py
@@ -124,13 +124,13 @@ def _system_memory_gb() -> tuple[float, float]:
         import psutil
         vm = psutil.virtual_memory()
         return vm.total / 1024 ** 3, vm.available / 1024 ** 3
-    except ImportError:
+    except (AttributeError, ImportError, OSError, RuntimeError, ValueError):
         pass
     try:
         total = os.sysconf("SC_PHYS_PAGES") * os.sysconf("SC_PAGE_SIZE") / 1024 ** 3
         # Rough estimate: assume 60 % available if we can't query
         return total, total * 0.6
-    except (AttributeError, ValueError):
+    except (AttributeError, OSError, ValueError):
         return 16.0, 8.0  # conservative fallback
 
 
diff --git a/tests/test_device_boundaries.py b/tests/test_device_boundaries.py
index e493050..327b966 100644
--- a/tests/test_device_boundaries.py
+++ b/tests/test_device_boundaries.py
@@ -71,6 +71,14 @@ def test_system_memory_sources_and_fallback(monkeypatch):
     monkeypatch.setitem(__import__("sys").modules, "psutil", fake_psutil)
     assert device._system_memory_gb() == (32.0, 12.0)
 
+    fake_psutil.virtual_memory = Mock(side_effect=FileNotFoundError("/proc/meminfo"))
+    monkeypatch.setattr(
+        device.os,
+        "sysconf",
+        lambda name: {"SC_PHYS_PAGES": 4, "SC_PAGE_SIZE": gib}[name],
+    )
+    assert device._system_memory_gb() == (4.0, 2.4)
+
     monkeypatch.delitem(__import__("sys").modules, "psutil", raising=False)
     real_import = __import__("builtins").__import__