diff --git a/core/sources/civarchive.py b/core/sources/civarchive.py
index 11c6029..14e6137 100644
--- a/core/sources/civarchive.py
+++ b/core/sources/civarchive.py
@@ -501,11 +501,14 @@ def _base_model_matches(candidate: str, preferred: Optional[str]) -> bool:
 
     from .popular import load_base_model_aliases
     aliases = load_base_model_aliases()
+    # Exact alias membership check - avoids false positives from substring matching
+    # e.g. prevents "zimage" (Z-Image alias) from matching "zimagebase" (ZImageBase)
     preferred_tokens = aliases.get(preferred_norm, [preferred_norm])
-    return any(
-        token and (token in candidate_norm or candidate_norm in token)
-        for token in preferred_tokens
-    )
+    if candidate_norm in preferred_tokens:
+        return True
+    # Symmetric check: if preferred is an alias of candidate's model family
+    candidate_tokens = aliases.get(candidate_norm, [candidate_norm])
+    return preferred_norm in candidate_tokens
 
 
 def _base_model_score(candidate: str, preferred: Optional[str]) -> float:
diff --git a/core/sources/civitai.py b/core/sources/civitai.py
index 79be7b8..f0824f2 100644
--- a/core/sources/civitai.py
+++ b/core/sources/civitai.py
@@ -276,11 +276,14 @@ def _base_model_matches(candidate: str, preferred: Optional[str]) -> bool:
 
     from .popular import load_base_model_aliases
     aliases = load_base_model_aliases()
+    # Exact alias membership check - avoids false positives from substring matching
+    # e.g. prevents "zimage" (Z-Image alias) from matching "zimagebase" (ZImageBase)
     preferred_tokens = aliases.get(preferred_norm, [preferred_norm])
-    return any(
-        token and (token in candidate_norm or candidate_norm in token)
-        for token in preferred_tokens
-    )
+    if candidate_norm in preferred_tokens:
+        return True
+    # Symmetric check: if preferred is an alias of candidate's model family
+    candidate_tokens = aliases.get(candidate_norm, [candidate_norm])
+    return preferred_norm in candidate_tokens
 
 
 def _base_model_score(candidate: str, preferred: Optional[str]) -> float:
diff --git a/core/sources/lora_manager_archive.py b/core/sources/lora_manager_archive.py
index 968c738..2990e19 100644
--- a/core/sources/lora_manager_archive.py
+++ b/core/sources/lora_manager_archive.py
@@ -168,11 +168,14 @@ def _base_model_matches(candidate: str, preferred: Optional[str]) -> bool:
 
     from .popular import load_base_model_aliases
     aliases = load_base_model_aliases()
+    # Exact alias membership check - avoids false positives from substring matching
+    # e.g. prevents "zimage" (Z-Image alias) from matching "zimagebase" (ZImageBase)
     preferred_tokens = aliases.get(preferred_norm, [preferred_norm])
-    return any(
-        token and (token in candidate_norm or candidate_norm in token)
-        for token in preferred_tokens
-    )
+    if candidate_norm in preferred_tokens:
+        return True
+    # Symmetric check: if preferred is an alias of candidate's model family
+    candidate_tokens = aliases.get(candidate_norm, [candidate_norm])
+    return preferred_norm in candidate_tokens
 
 
 def _base_model_score(candidate: str, preferred: Optional[str]) -> float:
diff --git a/metadata/base-models.meta.json b/metadata/base-models.meta.json
index c3b7b86..fdb2e42 100644
--- a/metadata/base-models.meta.json
+++ b/metadata/base-models.meta.json
@@ -1,6 +1,6 @@
 {
-  "updated_at": "2026-06-06T17:28:12+00:00",
-  "last_checked_at": "2026-06-06T17:28:12+00:00",
+  "updated_at": "2026-06-06T17:43:51+00:00",
+  "last_checked_at": "2026-06-06T17:43:51+00:00",
   "local_count": 91,
-  "new_models_added": 79
+  "new_models_added": 0
 }