diff --git a/src/adaptations/device-layer/include/Weave/DeviceLayer/internal/GenericConfigurationManagerImpl.ipp b/src/adaptations/device-layer/include/Weave/DeviceLayer/internal/GenericConfigurationManagerImpl.ipp
index 8e56e66..9551759 100644
--- a/src/adaptations/device-layer/include/Weave/DeviceLayer/internal/GenericConfigurationManagerImpl.ipp
+++ b/src/adaptations/device-layer/include/Weave/DeviceLayer/internal/GenericConfigurationManagerImpl.ipp
@@ -1057,7 +1057,7 @@
 {
     constexpr uint16_t kInputBufSize = 80;
     static_assert(kInputBufSize > 0 && kInputBufSize % 4 == 0, "kInputBufSize must be a positive multiple of 4");
-    char inputBuf[kInputBufSize];
+    char inputBuf[kInputBufSize + 1];
     constexpr uint16_t kMaxChunkLen = BASE64_MAX_DECODED_LEN(kInputBufSize);
 
     // Hash the length of the base-64 value as 4 hex digits.