diff --git a/graphify/analyze.py b/graphify/analyze.py
index 5f28179..8aaf6c1 100644
--- a/graphify/analyze.py
+++ b/graphify/analyze.py
@@ -686,8 +686,11 @@ def find_import_cycles(
         return []
 
     # Step 2: Find simple cycles, bounded by length.
+    # Pass length_bound so networkx prunes during enumeration rather than
+    # enumerating all elementary cycles and post-filtering — avoids exponential
+    # blowup on dense graphs with many long cycles (#1196).
     cycles: list[list[str]] = []
-    for cycle in nx.simple_cycles(file_graph):
+    for cycle in nx.simple_cycles(file_graph, length_bound=max_cycle_length):
         if len(cycle) <= max_cycle_length:
             cycles.append(cycle)
         if len(cycles) >= top_n * 10:
diff --git a/graphify/dedup.py b/graphify/dedup.py
index 913975a..e37b4c7 100644
--- a/graphify/dedup.py
+++ b/graphify/dedup.py
@@ -245,6 +245,13 @@ def deduplicate_entities(
                     continue
                 if _short_label_blocked(norm_label, neighbor_norm, score):
                     continue
+                # Prefix-extension pairs (getActiveSession / getActiveSessions,
+                # parseConfig / parseConfigFile) are almost never duplicates —
+                # one is a strict suffix-extension of the other. Block the merge
+                # regardless of JW score (#1201).
+                _lo, _hi = sorted((norm_label, neighbor_norm), key=len)
+                if _hi.startswith(_lo) and _hi != _lo:
+                    continue
 
                 c1 = communities.get(node_id)
                 c2 = communities.get(neighbor_id)
@@ -372,6 +379,9 @@ def _llm_tiebreak(
                 continue
             if _short_label_blocked(norm_i, norm_j, score):
                 continue
+            _lo, _hi = sorted((norm_i, norm_j), key=len)
+            if _hi.startswith(_lo) and _hi != _lo:
+                continue
             c1 = communities.get(node["id"])
             c2 = communities.get(neighbor["id"])
             if (c1 is not None and c2 is not None and c1 == c2
diff --git a/graphify/llm.py b/graphify/llm.py
index 93725f2..513c1e5 100644
--- a/graphify/llm.py
+++ b/graphify/llm.py
@@ -1890,7 +1890,10 @@ def label_communities(
             "Respond ONLY with a JSON object mapping the community id (as a string) to "
             "its name - no prose, no markdown fences.\n\n" + "\n".join(batch_lines)
         )
-        max_tokens = min(40 + 16 * len(batch_cids), 4096)
+        # 24 tok/community covers 2-5 word JSON entries including id, quotes,
+        # and punctuation. Cap at 8192 for 16k-context models. Wrapped in
+        # _resolve_max_tokens so GRAPHIFY_MAX_OUTPUT_TOKENS applies here too (#1200).
+        max_tokens = _resolve_max_tokens(min(64 + 24 * len(batch_cids), 8192))
         try:
             text = _call_llm(prompt, backend=backend, max_tokens=max_tokens)
             parsed = _parse_label_response(text, batch_cids)
diff --git a/tests/test_dedup.py b/tests/test_dedup.py
index 293d2a8..419f009 100644
--- a/tests/test_dedup.py
+++ b/tests/test_dedup.py
@@ -177,3 +177,64 @@ def test_variant_pair_helper():
     assert _is_variant_pair("cortex a55", "cortex a55x")
     assert not _is_variant_pair("graphextractor", "graphextracter")
     assert not _is_variant_pair("foo", "foo")
+
+
+def test_prefix_extension_symbols_not_merged():
+    """Distinct symbols whose name is a strict prefix-extension of another must not
+    be merged (#1201). getActiveSession / getActiveSessions score ~98.82 JW but are
+    different functions; parseConfig / parseConfigFile likewise."""
+    import networkx as nx
+    from graphify.dedup import deduplicate_entities
+
+    pairs = [
+        ("getActiveSession", "getActiveSessions"),
+        ("parseConfig", "parseConfigFile"),
+        ("load", "loadAll"),
+        ("handleRequest", "handleRequestTimeout"),
+    ]
+    for a, b in pairs:
+        nodes = [
+            {"id": f"{a}_id", "label": a, "type": "CODE", "src_file": "api.py"},
+            {"id": f"{b}_id", "label": b, "type": "CODE", "src_file": "api.py"},
+        ]
+        edges = [{"src": f"{a}_id", "tgt": f"{b}_id", "relation": "calls",
+                  "c": 1.0, "weight": 1.0}]
+        out_nodes, _ = deduplicate_entities(
+            nodes, edges, communities={f"{a}_id": 0, f"{b}_id": 0}
+        )
+        labels = {n["label"] for n in out_nodes}
+        assert a in labels and b in labels, (
+            f"#1201 regression: '{a}' and '{b}' were merged — they are distinct symbols"
+        )
+
+
+def test_prefix_guard_does_not_block_same_length_typos():
+    """The prefix-extension guard must not fire for same-length pairs — only strict
+    prefix-extensions (one is a substring of the other) should be blocked (#1201).
+    graphextractor / graphextractar have the same length, so neither starts-with the
+    other, and the guard must not fire."""
+    from graphify.dedup import _norm
+    a = _norm("GraphExtractor")   # "graphextractor" — 14 chars
+    b = _norm("GraphExtractar")   # "graphextractar" — 14 chars
+    lo, hi = sorted((a, b), key=len)
+    # Same-length pair: startswith only holds when strings are identical
+    assert not (hi.startswith(lo) and hi != lo), (
+        f"Prefix guard fires on same-length pair ({a!r}, {b!r}) — should not"
+    )
+
+
+def test_prefix_guard_fires_for_extension_pairs():
+    """The prefix-extension guard must fire for pairs where one is a strict prefix
+    of the other, preventing false merges (#1201)."""
+    from graphify.dedup import _norm
+    pairs = [
+        ("getActiveSession", "getActiveSessions"),
+        ("parseConfig", "parseConfigFile"),
+        ("load", "loadAll"),
+    ]
+    for a_raw, b_raw in pairs:
+        a, b = _norm(a_raw), _norm(b_raw)
+        lo, hi = sorted((a, b), key=len)
+        assert hi.startswith(lo) and hi != lo, (
+            f"Prefix guard should fire for ({a!r}, {b!r}) but did not"
+        )