diff --git a/Framework/Core/include/Framework/HistogramSpec.h b/Framework/Core/include/Framework/HistogramSpec.h
index 365b2255eeb99..47c3d7f1c6170 100644
--- a/Framework/Core/include/Framework/HistogramSpec.h
+++ b/Framework/Core/include/Framework/HistogramSpec.h
@@ -99,6 +99,23 @@ struct AxisSpec {
   // first entry is assumed to be the number of bins; in case of variable size binning it must be set to zero
   AxisSpec(ConfigurableAxis binEdges_, std::optional<std::string> title_ = std::nullopt, std::optional<std::string> name_ = std::nullopt);
 
+  // Out of line too, and for the same reason: every registry.add() call site
+  // materialises AxisSpec temporaries, so the *destructor* is expanded there as
+  // well -- on both the normal and the exception-unwind path. Measured with
+  // -Rpass=inline on a 276-histogram init(): ~optional<string> inlined 2164
+  // times, ~vector<AxisSpec> 552, ~vector<double> 367, ~AxisSpec 279.
+  //
+  // Declaring a destructor suppresses the implicit move operations, so all five
+  // are declared here to keep AxisSpec movable. The moves are explicitly
+  // noexcept: an out-of-line defaulted function does NOT inherit the implicit
+  // exception specification, and without it vector<AxisSpec> reallocation would
+  // silently fall back to copying.
+  ~AxisSpec();
+  AxisSpec(AxisSpec const&);
+  AxisSpec(AxisSpec&&) noexcept;
+  AxisSpec& operator=(AxisSpec const&);
+  AxisSpec& operator=(AxisSpec&&) noexcept;
+
   [[nodiscard]] long getNbins() const;
 
   /// Function to make the axis logarithmic
@@ -122,6 +139,10 @@ struct HistogramConfigSpec {
   HistogramConfigSpec() = default;
   HistogramConfigSpec(HistogramConfigSpec const& other) = default;
   HistogramConfigSpec(HistogramConfigSpec&& other) = default;
+  // Out of line: inlined 552 times into a single 276-histogram init().
+  // The copy/move constructors above stay declared, so this does not suppress
+  // them.
+  ~HistogramConfigSpec();
 
   void addAxis(const AxisSpec& axis)
   {
diff --git a/Framework/Core/src/HistogramSpec.cxx b/Framework/Core/src/HistogramSpec.cxx
index 496a07a6dcba4..282b3de18674b 100644
--- a/Framework/Core/src/HistogramSpec.cxx
+++ b/Framework/Core/src/HistogramSpec.cxx
@@ -58,6 +58,15 @@ HistogramConfigSpec::HistogramConfigSpec(HistType type_, std::vector<AxisSpec> a
 {
 }
 
+// Out of line: see the comments on the declarations in HistogramSpec.h.
+AxisSpec::~AxisSpec() = default;
+AxisSpec::AxisSpec(AxisSpec const&) = default;
+AxisSpec::AxisSpec(AxisSpec&&) noexcept = default;
+AxisSpec& AxisSpec::operator=(AxisSpec const&) = default;
+AxisSpec& AxisSpec::operator=(AxisSpec&&) noexcept = default;
+
+HistogramConfigSpec::~HistogramConfigSpec() = default;
+
 void AxisSpec::makeLogarithmic()
 {
   if (binEdges.size() > 2) {