diff --git a/src/ipa/ipu3/algorithms/awb.cpp b/src/ipa/ipu3/algorithms/awb.cpp
index 62c72cce..1ffb431b 100644
--- a/src/ipa/ipu3/algorithms/awb.cpp
+++ b/src/ipa/ipu3/algorithms/awb.cpp
@@ -17,7 +17,13 @@ namespace ipa::ipu3::algorithms {
 
 LOG_DEFINE_CATEGORY(IPU3Awb)
 
-static constexpr uint32_t kMinGreenLevelInZone = 32;
+/*
+ * When zones are used for the grey world algorithm, they are only considered if
+ * their average green value is at least 16/255 to exclude zones that are too
+ * dark and don't provide relevant colour information (on the opposite side of
+ * the spectrum, saturated regions are excluded by the ImgU statistics engine).
+ */
+static constexpr uint32_t kMinGreenLevelInZone = 16;
 
 /* Minimum proportion of cells counted within a zone for it to be relevant */
 static constexpr double kMinRelevantCellsRatio = 0.8;