diff --git a/app/heuristics/__init__.py b/app/heuristics/__init__.py
index 7532b397..6504ac81 100644
--- a/app/heuristics/__init__.py
+++ b/app/heuristics/__init__.py
@@ -704,7 +704,11 @@ def detect_coding_context(text: str) -> bool:
     r"istisna",
 ]
 
-_JOINED_LIVE_DEBUG = re.compile("|".join(LIVE_DEBUG_KEYWORDS))
+# Word boundaries prevent substring false positives: "logs?" must not match
+# inside "login"/"blog"/"catalog", "mre" inside unrelated tokens, etc. The
+# keywords intentionally contain regex (e.g. "logs?"), so we wrap with \b rather
+# than re.escape. Mirrors the fix already applied to _TEACHING_RE above.
+_JOINED_LIVE_DEBUG = re.compile("|".join(rf"\b{keyword}\b" for keyword in LIVE_DEBUG_KEYWORDS))
 
 
 def detect_live_debug(text: str) -> bool:
diff --git a/tests/test_detect_live_debug.py b/tests/test_detect_live_debug.py
index 0dce4b15..8a5ce9a1 100644
--- a/tests/test_detect_live_debug.py
+++ b/tests/test_detect_live_debug.py
@@ -11,3 +11,20 @@ def test_detect_live_debug_false_cases():
     assert detect_live_debug("How do I write a Python function?") is False
     assert detect_live_debug("Explain quantum physics") is False
     assert detect_live_debug("") is False
+
+
+def test_detect_live_debug_ignores_substring_false_positives():
+    # Keywords like "logs?" must not substring-match unrelated words such as
+    # "login", "blog", "catalog", or "dialog" (regression for the missing
+    # word boundaries in _JOINED_LIVE_DEBUG).
+    assert detect_live_debug("Implement secure login sessions") is False
+    assert detect_live_debug("write a blog post") is False
+    assert detect_live_debug("browse the catalog") is False
+    assert detect_live_debug("open the dialog box") is False
+
+
+def test_detect_live_debug_matches_log_and_debug_keywords():
+    # Genuine log/debug cues must still be detected once word boundaries are added.
+    assert detect_live_debug("check the error log") is True
+    assert detect_live_debug("attach the logs") is True
+    assert detect_live_debug("help me debug this stack trace") is True