diff --git a/code-reviews/Driver.AbLegacy/findings.md b/code-reviews/Driver.AbLegacy/findings.md
index a1d8028..8759f10 100644
--- a/code-reviews/Driver.AbLegacy/findings.md
+++ b/code-reviews/Driver.AbLegacy/findings.md
@@ -117,7 +117,7 @@ reject file numbers on I/O/S, and restrict which file letters may carry a sub-el
 | Severity | Medium |
 | Category | Correctness & logic bugs |
 | Location | `LibplctagLegacyTagRuntime.cs:36-37` |
-| Status | Open |
+| Status | Resolved |
 
 **Description:** `DecodeValue` for `AbLegacyDataType.Bit` with `bitIndex == null`
 returns `_tag.GetInt8(0) != 0`. A bit-file element (`B3:0/0`) is a single bit inside
@@ -132,7 +132,7 @@ but a `Bit`-typed tag configured with an address that has no `/bit` suffix (e.g.
 bit suffix on `Bit`-typed tags (validate in `CreateInstance`/`DiscoverAsync`) or
 decode the full 16-bit word and test bit 0.
 
-**Resolution:** _(open)_
+**Resolution:** Resolved 2026-05-22 — `DecodeValue` for `Bit` with no `bitIndex` now reads the full 16-bit word via `GetInt16(0)` and tests bit 0, avoiding the silent half-word truncation from `GetInt8`.
 
 ### Driver.AbLegacy-005
 
diff --git a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy/LibplctagLegacyTagRuntime.cs b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy/LibplctagLegacyTagRuntime.cs
index 3f8e1aa..d28227a 100644
--- a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy/LibplctagLegacyTagRuntime.cs
+++ b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy/LibplctagLegacyTagRuntime.cs
@@ -33,9 +33,13 @@ internal sealed class LibplctagLegacyTagRuntime : IAbLegacyTagRuntime
 
     public object? DecodeValue(AbLegacyDataType type, int? bitIndex) => type switch
     {
+        // When a bit suffix is present (e.g. B3:0/5) libplctag resolves the individual bit and
+        // GetBit returns it directly. When there is no suffix the caller addressed a Bit-typed
+        // tag without an explicit bit index; read the full 16-bit word and test bit 0 — GetInt8
+        // only covers the low byte and silently misses any bit set in bits 8..15.
         AbLegacyDataType.Bit => bitIndex is int bit
             ? _tag.GetBit(bit)
-            : _tag.GetInt8(0) != 0,
+            : (_tag.GetInt16(0) & 1) != 0,
         AbLegacyDataType.Int or AbLegacyDataType.AnalogInt => (int)_tag.GetInt16(0),
         AbLegacyDataType.Long => _tag.GetInt32(0),
         AbLegacyDataType.Float => _tag.GetFloat32(0),