diff --git a/src/ipa/rkisp1/algorithms/agc.cpp b/src/ipa/rkisp1/algorithms/agc.cpp
index 47a6f7b2..278903a5 100644
--- a/src/ipa/rkisp1/algorithms/agc.cpp
+++ b/src/ipa/rkisp1/algorithms/agc.cpp
@@ -352,7 +352,7 @@ double Agc::estimateLuminance(Span<const uint8_t> expMeans, double gain)
  */
 double Agc::measureBrightness(Span<const uint32_t> hist) const
 {
-	Histogram histogram{ hist };
+	Histogram histogram{ hist, 4 };
 	/* Estimate the quantile mean of the top 2% of the histogram. */
 	return histogram.interQuantileMean(0.98, 1.0);
 }