diff --git a/src/platform/Ameba/AmebaConfig.cpp b/src/platform/Ameba/AmebaConfig.cpp
index b9ac5d05b789f2..8cc287585ddc6a 100644
--- a/src/platform/Ameba/AmebaConfig.cpp
+++ b/src/platform/Ameba/AmebaConfig.cpp
@@ -152,6 +152,7 @@ CHIP_ERROR AmebaConfig::ReadConfigValueStr(Key key, char * buf, size_t bufSize,
 
     if (success == 0)
     {
+        outLen -= 1; // Don't count trailing null
         return CHIP_NO_ERROR;
     }
     else