diff --git a/src/highs_bindings.cpp b/src/highs_bindings.cpp
index e7f9e49cac..06cd4f70c2 100644
--- a/src/highs_bindings.cpp
+++ b/src/highs_bindings.cpp
@@ -1195,12 +1195,11 @@ PYBIND11_MODULE(_core, m) {
       .def_property(
           "mip_solution",
           [](const HighsCallbackDataOut& self) -> py::array {
-            // XXX: This is clearly wrong, most likely we need to have the
-            // length as an input data parameter
-            return py::array(3, self.mip_solution);
+            return py::array(self.mip_solution_size, self.mip_solution);
           },
           [](HighsCallbackDataOut& self, py::array_t<double> new_mip_solution) {
                       self.mip_solution = new_mip_solution.mutable_data();
+                      self.mip_solution_size = new_mip_solution.shape(0);
           });
   py::class_<HighsCallbackDataIn>(callbacks, "HighsCallbackDataIn")
       .def(py::init<>())
diff --git a/src/lp_data/HighsCallbackStruct.h b/src/lp_data/HighsCallbackStruct.h
index a5f7140834..1429625ea3 100644
--- a/src/lp_data/HighsCallbackStruct.h
+++ b/src/lp_data/HighsCallbackStruct.h
@@ -37,6 +37,7 @@ typedef struct {
   double mip_dual_bound;
   double mip_gap;
   double* mip_solution;
+  HighsInt mip_solution_size;
   HighsInt cutpool_num_col;
   HighsInt cutpool_num_cut;
   HighsInt cutpool_num_nz;
diff --git a/src/lp_data/HighsModelUtils.cpp b/src/lp_data/HighsModelUtils.cpp
index 0e4db30085..5d887167b7 100644
--- a/src/lp_data/HighsModelUtils.cpp
+++ b/src/lp_data/HighsModelUtils.cpp
@@ -243,6 +243,7 @@ void writePrimalSolution(FILE* file, const HighsLogOptions& log_options,
     ss << "\n";
     highsFprintfString(file, log_options, ss.str());
   }
+  fflush(file);
 }
 
 void writeModelSolution(FILE* file, const HighsLogOptions& log_options,
diff --git a/src/mip/HighsMipSolverData.cpp b/src/mip/HighsMipSolverData.cpp
index 9dcd8129b6..4a2b7f25c5 100644
--- a/src/mip/HighsMipSolverData.cpp
+++ b/src/mip/HighsMipSolverData.cpp
@@ -463,6 +463,7 @@ void HighsMipSolverData::runSetup() {
       assert(!mipsolver.submip);
       mipsolver.callback_->clearHighsCallbackDataOut();
       mipsolver.callback_->data_out.mip_solution = mipsolver.solution_.data();
+      mipsolver.callback_->data_out.mip_solution_size = mipsolver.solution_.size();
       const bool interrupt = interruptFromCallbackWithData(
           kCallbackMipSolution, mipsolver.solution_objective_,
           "Feasible solution");
@@ -832,6 +833,7 @@ double HighsMipSolverData::transformNewIntegerFeasibleSolution(
       mipsolver.callback_->active[kCallbackMipSolution]) {
     mipsolver.callback_->clearHighsCallbackDataOut();
     mipsolver.callback_->data_out.mip_solution = solution.col_value.data();
+    mipsolver.callback_->data_out.mip_solution_size = solution.col_value.size();
     const bool interrupt = interruptFromCallbackWithData(
         kCallbackMipSolution, mipsolver_objective_value, "Feasible solution");
     assert(!interrupt);
@@ -1928,6 +1930,7 @@ void HighsMipSolverData::saveReportMipSolution(const double new_upper_limit) {
     if (mipsolver.callback_->active[kCallbackMipImprovingSolution]) {
       mipsolver.callback_->clearHighsCallbackDataOut();
       mipsolver.callback_->data_out.mip_solution = mipsolver.solution_.data();
+      mipsolver.callback_->data_out.mip_solution_size = mipsolver.solution_.size();
       const bool interrupt = interruptFromCallbackWithData(
           kCallbackMipImprovingSolution, mipsolver.solution_objective_,
           "Improving solution");