diff --git a/opm/simulators/flow/SimulatorFullyImplicitBlackoilEbos.cpp b/opm/simulators/flow/SimulatorFullyImplicitBlackoilEbos.cpp
index bfb4e14d1..e2c8df1b7 100644
--- a/opm/simulators/flow/SimulatorFullyImplicitBlackoilEbos.cpp
+++ b/opm/simulators/flow/SimulatorFullyImplicitBlackoilEbos.cpp
@@ -22,11 +22,14 @@
 #include <config.h>
 
 #include <opm/common/OpmLog/OpmLog.hpp>
+#include <opm/common/utility/String.hpp>
+
 #include <opm/input/eclipse/Units/Units.hpp>
 #include <opm/simulators/timestepping/SimulatorTimer.hpp>
 
 #include <boost/date_time.hpp>
 
+#include <algorithm>
 #include <sstream>
 #include <string>
 
@@ -61,4 +64,74 @@ void outputTimestampFIP(const SimulatorTimer& timer,
     OpmLog::note(ss.str());
 }
 
+void checkSerializedCmdLine(const std::string& current,
+                            const std::string& stored)
+{
+    auto filter_strings = [](const std::vector<std::string>& input)
+    {
+        std::vector<std::string> output;
+        output.reserve(input.size());
+        std::copy_if(input.begin(), input.end(), std::back_inserter(output),
+                     [](const std::string& line)
+                     {
+                        return line.compare(0, 11, "EclDeckFile") != 0 &&
+                               line.compare(0, 8, "LoadStep") != 0 &&
+                               line.compare(0, 8, "SaveFile") != 0 &&
+                               line.compare(0, 8, "SaveStep") != 0;
+                     });
+        return output;
+    };
+
+    auto curr_strings = split_string(current, '\n');
+    auto stored_strings = split_string(stored, '\n');
+    std::sort(curr_strings.begin(), curr_strings.end());
+    std::sort(stored_strings.begin(), stored_strings.end());
+    curr_strings = filter_strings(curr_strings);
+    stored_strings = filter_strings(stored_strings);
+
+    std::vector<std::string> difference;
+    std::set_symmetric_difference(stored_strings.begin(), stored_strings.end(),
+                                  curr_strings.begin(), curr_strings.end(),
+                                  std::back_inserter(difference));
+
+    std::vector<std::string> only_stored, only_curr;
+    if (!difference.empty()) {
+        for (size_t i = 0; i < difference.size(); ) {
+            auto stored_it = std::find(stored_strings.begin(),
+                                       stored_strings.end(), difference[i]);
+            auto pos = difference[i].find_first_of('=');
+            if (i < difference.size() - 1 &&
+                difference[i].compare(0, pos, difference[i+1], 0, pos) == 0) {
+                if (stored_it == stored_strings.end()) {
+                    std::swap(difference[i], difference[i+1]);
+                }
+                i += 2;
+            } else {
+                if (stored_it == stored_strings.end()) {
+                    only_curr.push_back(difference[i]);
+                } else {
+                    only_stored.push_back(difference[i]);
+                }
+                difference.erase(difference.begin() + i);
+            }
+        }
+        std::stringstream str;
+        str << "Differences:\n";
+        for (std::size_t i = 0; i < difference.size(); ++i) {
+            str << '\t' << (i % 2 == 0 ? '-' : '+') << difference[i] << '\n';
+        }
+        if (!only_stored.empty()) {
+            str << "Only in serialized parameters:\n";
+            for (const std::string& line : only_stored)
+                str << '\t' << line << '\n';
+        }
+        if (!only_curr.empty()) {
+            str << "Only in current parameters:\n";
+            for (const std::string& line : only_curr)
+                str << '\t' << line << '\n';
+        }
+        OpmLog::warning("Command line parameters mismatch:\n" + str.str());
+    }
+}
+
 } // namespace Opm
diff --git a/opm/simulators/flow/SimulatorFullyImplicitBlackoilEbos.hpp b/opm/simulators/flow/SimulatorFullyImplicitBlackoilEbos.hpp
index 631ddd95c..162f57e21 100644
--- a/opm/simulators/flow/SimulatorFullyImplicitBlackoilEbos.hpp
+++ b/opm/simulators/flow/SimulatorFullyImplicitBlackoilEbos.hpp
@@ -135,6 +135,8 @@ void outputReportStep(const SimulatorTimer& timer);
 void outputTimestampFIP(const SimulatorTimer& timer,
                         const std::string& title,
                         const std::string& version);
+void checkSerializedCmdLine(const std::string& current,
+                            const std::string& stored);
 
 /// a simulator for the blackoil model
 template<class TypeTag>
@@ -644,16 +646,33 @@ protected:
         const std::string groupName = "/report_step/" + std::to_string(loadStep_);
         reader.read(timer, groupName, "simulator_timer", HDF5File::DataSetMode::ROOT_ONLY);
 
+        std::tuple<std::array<std::string,5>,int> header;
+        reader.read(header, "/", "simulator_info", HDF5File::DataSetMode::ROOT_ONLY);
+        const auto& [strings, procs] = header;
+
+        if (EclGenericVanguard::comm().size() != procs) {
+            throw std::runtime_error("Number of processes (procs=" +
+                                     std::to_string(EclGenericVanguard::comm().size()) +
+                                     ") does not match .OPMRST file (procs=" +
+                                     std::to_string(procs) + ")");
+        }
+
         if (EclGenericVanguard::comm().size() > 1) {
             std::size_t stored_hash;
             reader.read(stored_hash, "/", "grid_checksum");
             const auto& cellMapping = ebosSimulator_.vanguard().globalCell();
             std::size_t hash = Dune::hash_range(cellMapping.begin(), cellMapping.end());
             if (hash != stored_hash) {
-                throw std::runtime_error("Grid hash mismatch, .SAVE file cannot be used");
+                throw std::runtime_error("Grid hash mismatch, .OPMRST file cannot be used");
             }
         }
 
+        if (EclGenericVanguard::comm().rank() == 0) {
+            std::ostringstream str;
+            Parameters::printValues<TypeTag>(str);
+            checkSerializedCmdLine(str.str(), strings[4]);
+        }
+
         OPM_END_PARALLEL_TRY_CATCH("Error loading serialized state: ",
                                    EclGenericVanguard::comm());
 #endif