diff --git a/image_analysis/IndexAndRefine.cpp b/image_analysis/IndexAndRefine.cpp
index 186bfc04..9a2023dd 100644
--- a/image_analysis/IndexAndRefine.cpp
+++ b/image_analysis/IndexAndRefine.cpp
@@ -275,7 +275,7 @@ std::optional<RotationIndexerResult> IndexAndRefine::Finalize() {
 }
 
 IndexAndRefine &IndexAndRefine::ReferenceIntensities(std::vector<MergedReflection> &reference) {
-    scaling_engine = std::make_unique<ScaleOnTheFly>(reference, experiment);
+    scaling_engine = std::make_unique<ScaleOnTheFly>(experiment, reference);
     return *this;
 }
 
@@ -299,7 +299,7 @@ void IndexAndRefine::ScaleImage(DataMessage &msg) {
 }
 
 ScalingResult IndexAndRefine::ScaleAllImages(const std::vector<MergedReflection> &reference, size_t nthreads) {
-    ScaleOnTheFly scaling(reference, experiment);
+    ScaleOnTheFly scaling(experiment, reference);
     auto result = scaling.Scale(reflections, mosaicity, nthreads);
     merge_mask = CalcMergeMask(experiment, result);
     return result;
diff --git a/image_analysis/scale_merge/ScaleOnTheFly.cpp b/image_analysis/scale_merge/ScaleOnTheFly.cpp
index be7c086c..b70dd255 100644
--- a/image_analysis/scale_merge/ScaleOnTheFly.cpp
+++ b/image_analysis/scale_merge/ScaleOnTheFly.cpp
@@ -87,7 +87,7 @@ namespace {
     };
 }
 
-ScaleOnTheFly::ScaleOnTheFly(const std::vector<MergedReflection> &ref, const DiffractionExperiment &x)
+ScaleOnTheFly::ScaleOnTheFly(const DiffractionExperiment &x, const std::vector<MergedReflection> &ref)
     : sg(x.GetGemmiSpaceGroup()),
       model(x.GetPartialityModel()),
       s(x.GetScalingSettings()),
diff --git a/image_analysis/scale_merge/ScaleOnTheFly.h b/image_analysis/scale_merge/ScaleOnTheFly.h
index fac68f3b..67007a23 100644
--- a/image_analysis/scale_merge/ScaleOnTheFly.h
+++ b/image_analysis/scale_merge/ScaleOnTheFly.h
@@ -36,7 +36,7 @@ class ScaleOnTheFly {
     bool Accept(const Reflection &r);
     [[nodiscard]] std::pair<double, size_t> CalculateGlobalCC(const std::vector<Reflection> &reflections) const;
 public:
-    ScaleOnTheFly(const std::vector<MergedReflection> &ref, const DiffractionExperiment &x);
+    ScaleOnTheFly(const DiffractionExperiment &x, const std::vector<MergedReflection> &ref);
     ScaleOnTheFlyResult Scale(std::vector<Reflection> &r, std::optional<double> mosaicity_deg);
 
     ScalingResult Scale(std::vector<std::vector<Reflection> > &reflections,
diff --git a/tools/jfjoch_scale.cpp b/tools/jfjoch_scale.cpp
index 5c14e1a1..8dd9531b 100644
--- a/tools/jfjoch_scale.cpp
+++ b/tools/jfjoch_scale.cpp
@@ -250,11 +250,11 @@ auto mosaicity = dataset->mosaicity_deg;
 
         if (reference_data.empty()) {
             auto merged = MergeAll(experiment, reflections);
-            ScaleOnTheFly scaling(merged, experiment);
+            ScaleOnTheFly scaling(experiment, merged);
             // TODO: Fix mosaicty
             scale_result = scaling.Scale(reflections,{});
         } else {
-            ScaleOnTheFly scaling(reference_data, experiment);
+            ScaleOnTheFly scaling(experiment, reference_data);
             scale_result = scaling.Scale(reflections,{});
         }