diff --git a/modules/audio_processing/aec3/adaptive_fir_filter.cc b/modules/audio_processing/aec3/adaptive_fir_filter.cc
index 9bea40bbf1..f44fe3d743 100644
--- a/modules/audio_processing/aec3/adaptive_fir_filter.cc
+++ b/modules/audio_processing/aec3/adaptive_fir_filter.cc
@@ -504,6 +504,9 @@ void AdaptiveFirFilter::ResetFilterBuffersToCurrentSize() {
   H_.resize(current_size_partitions_);
   H2_.resize(current_size_partitions_);
   h_.resize(GetTimeDomainLength(current_size_partitions_));
+  RTC_DCHECK_LT(0, current_size_partitions_);
+  partition_to_constrain_ =
+      std::min(partition_to_constrain_, current_size_partitions_ - 1);
 }
 
 void AdaptiveFirFilter::UpdateSize() {