diff --git a/lib/api/CDataFrameOutliersRunner.cc b/lib/api/CDataFrameOutliersRunner.cc
index 67027669a3..7732c50dbc 100644
--- a/lib/api/CDataFrameOutliersRunner.cc
+++ b/lib/api/CDataFrameOutliersRunner.cc
@@ -118,9 +118,12 @@ void CDataFrameOutliersRunner::runImpl(core::CDataFrame& frame) {
                                                 m_NumberNeighbours,
                                                 m_ComputeFeatureInfluence,
                                                 m_OutlierFraction};
-    maths::COutliers::compute(params, frame, this->progressRecorder(), [](std::uint64_t memory) {
-        core::CProgramCounters::counter(counter_t::E_DFOPeakMemoryUsage).max(memory);
-    });
+    std::atomic<std::int64_t> memory{0};
+    maths::COutliers::compute(
+        params, frame, this->progressRecorder(), [&memory](std::int64_t delta) {
+            std::int64_t memory_{memory.fetch_add(delta)};
+            core::CProgramCounters::counter(counter_t::E_DFOPeakMemoryUsage).max(memory_);
+        });
 }
 
 std::size_t
diff --git a/lib/api/unittest/CDataFrameAnalyzerTest.cc b/lib/api/unittest/CDataFrameAnalyzerTest.cc
index 5c4973bc54..0c8e80f8e9 100644
--- a/lib/api/unittest/CDataFrameAnalyzerTest.cc
+++ b/lib/api/unittest/CDataFrameAnalyzerTest.cc
@@ -8,6 +8,7 @@
 
 #include <core/CContainerPrinter.h>
 #include <core/CJsonOutputStreamWrapper.h>
+#include <core/CProgramCounters.h>
 #include <core/CStringUtils.h>
 
 #include <maths/CBasicStatistics.h>
@@ -242,6 +243,13 @@ void CDataFrameAnalyzerTest::testRunOutlierDetection() {
     }
     CPPUNIT_ASSERT(expectedScore == expectedScores.end());
     CPPUNIT_ASSERT(progressCompleted);
+
+    LOG_DEBUG(<< "number partitions = "
+              << core::CProgramCounters::counter(counter_t::E_DFONumberPartitions));
+    LOG_DEBUG(<< "peak memory = "
+              << core::CProgramCounters::counter(counter_t::E_DFOPeakMemoryUsage));
+    CPPUNIT_ASSERT(core::CProgramCounters::counter(counter_t::E_DFONumberPartitions) == 1);
+    CPPUNIT_ASSERT(core::CProgramCounters::counter(counter_t::E_DFOPeakMemoryUsage) < 100000);
 }
 
 void CDataFrameAnalyzerTest::testRunOutlierDetectionPartitioned() {
@@ -281,6 +289,13 @@ void CDataFrameAnalyzerTest::testRunOutlierDetectionPartitioned() {
         }
     }
     CPPUNIT_ASSERT(expectedScore == expectedScores.end());
+
+    LOG_DEBUG(<< "number partitions = "
+              << core::CProgramCounters::counter(counter_t::E_DFONumberPartitions));
+    LOG_DEBUG(<< "peak memory = "
+              << core::CProgramCounters::counter(counter_t::E_DFOPeakMemoryUsage));
+    CPPUNIT_ASSERT(core::CProgramCounters::counter(counter_t::E_DFONumberPartitions) > 1);
+    CPPUNIT_ASSERT(core::CProgramCounters::counter(counter_t::E_DFOPeakMemoryUsage) < 110000); // + 10%
 }
 
 void CDataFrameAnalyzerTest::testRunOutlierFeatureInfluences() {