diff --git a/image_analysis/scale_merge/HKLKey.cpp b/image_analysis/scale_merge/HKLKey.cpp
index 3bdbfe61..6929b804 100644
--- a/image_analysis/scale_merge/HKLKey.cpp
+++ b/image_analysis/scale_merge/HKLKey.cpp
@@ -68,6 +68,14 @@ HKLKey HKLKeyGenerator::operator()(int32_t h, int32_t k, int32_t l) const {
     return key;
 }
 
+bool HKLKeyGenerator::IsSystematicallyAbsent(int32_t h, int32_t k, int32_t l) const {
+    return ops.is_systematically_absent(gemmi::Op::Miller{h, k, l});
+}
+
+bool HKLKeyGenerator::IsSystematicallyAbsent(const Reflection &r) const {
+    return IsSystematicallyAbsent(r.h, r.k, r.l);
+}
+
 bool AcceptReflection(const Reflection &r, std::optional<double> d_min_limit) {
     if (!std::isfinite(r.I))
         return false;
diff --git a/image_analysis/scale_merge/HKLKey.h b/image_analysis/scale_merge/HKLKey.h
index 51fbab48..70044c74 100644
--- a/image_analysis/scale_merge/HKLKey.h
+++ b/image_analysis/scale_merge/HKLKey.h
@@ -39,6 +39,9 @@ public:
     HKLKey operator()(const Reflection &r) const;
     HKLKey operator()(const MergedReflection &r) const;
     HKLKey operator()(int32_t h, int32_t k, int32_t l) const;
+
+    bool IsSystematicallyAbsent(int32_t h, int32_t k, int32_t l) const;
+    bool IsSystematicallyAbsent(const Reflection &r) const;
 };
 
 HKLKey CanonicalHKL(const Reflection &r, bool merge_friedel, const std::optional<gemmi::SpaceGroup> &sg);
diff --git a/image_analysis/scale_merge/Merge.cpp b/image_analysis/scale_merge/Merge.cpp
index 3c5e2fc4..4b383ddc 100644
--- a/image_analysis/scale_merge/Merge.cpp
+++ b/image_analysis/scale_merge/Merge.cpp
@@ -99,6 +99,9 @@ std::vector<MergedReflection> MergeAll(const DiffractionExperiment &x,
         if (reflections[i].empty())
             continue;
         for (const auto &r: reflections[i]) {
+            if (key_generator.IsSystematicallyAbsent(r))
+                continue;
+
             if (r.image_scale_corr <= 0.0 || !std::isfinite(r.image_scale_corr))
                 continue;
             if (!AcceptReflection(r, high_resolution_limit))
@@ -286,6 +289,9 @@ MergeStatistics MergeStats(const DiffractionExperiment &x,
             continue;
 
         for (const auto &r: reflections[i]) {
+            if (key_generator.IsSystematicallyAbsent(r))
+                continue;
+
             if (r.image_scale_corr <= 0.0 || !std::isfinite(r.image_scale_corr))
                 continue;