diff --git a/opm/simulators/wells/PerfData.cpp b/opm/simulators/wells/PerfData.cpp
index 121886c29..5d822d9e3 100644
--- a/opm/simulators/wells/PerfData.cpp
+++ b/opm/simulators/wells/PerfData.cpp
@@ -24,20 +24,22 @@ namespace Opm
 {
 
 
-PerfData::PerfData(std::size_t num_perf, const PhaseUsage& pu_arg):
+PerfData::PerfData(std::size_t num_perf, bool injector_, const PhaseUsage& pu_arg):
     pu(pu_arg),
+    injector(injector_),
     pressure(num_perf),
     rates(num_perf),
     phase_rates(num_perf * pu.num_phases),
     solvent_rates(num_perf),
     polymer_rates(num_perf),
     brine_rates(num_perf),
-    prod_index(num_perf * pu.num_phases),
-    water_throughput(num_perf),
-    skin_pressure(num_perf),
-    water_velocity(num_perf)
+    prod_index(num_perf * pu.num_phases)
 {
-
+    if (injector) {
+        this->water_throughput.resize(num_perf);
+        this->skin_pressure.resize(num_perf);
+        this->water_velocity.resize(num_perf);
+    }
 }
 
 std::size_t PerfData::size() const {
@@ -48,6 +50,9 @@ bool PerfData::try_assign(const PerfData& other) {
     if (this->size() != other.size())
         return false;
 
+    if (this->injector != other.injector)
+        return false;
+
     this->pressure = other.pressure;
     this->rates = other.rates;
     this->phase_rates = other.phase_rates;
@@ -58,7 +63,6 @@ bool PerfData::try_assign(const PerfData& other) {
     this->skin_pressure = other.skin_pressure;
     this->water_velocity = other.water_velocity;
     this->prod_index = other.prod_index;
-
     return true;
 }
 
diff --git a/opm/simulators/wells/PerfData.hpp b/opm/simulators/wells/PerfData.hpp
index 4187e7475..b663bfe72 100644
--- a/opm/simulators/wells/PerfData.hpp
+++ b/opm/simulators/wells/PerfData.hpp
@@ -32,9 +32,10 @@ class PerfData
 {
 private:
     PhaseUsage pu;
+    bool injector;
 
 public:
-    PerfData(std::size_t num_perf, const PhaseUsage& pu);
+    PerfData(std::size_t num_perf, bool injector_, const PhaseUsage& pu);
     std::size_t size() const;
     bool try_assign(const PerfData& other);
 
diff --git a/opm/simulators/wells/WellState.cpp b/opm/simulators/wells/WellState.cpp
index efcd2ce70..c52216b6e 100644
--- a/opm/simulators/wells/WellState.cpp
+++ b/opm/simulators/wells/WellState.cpp
@@ -100,7 +100,7 @@ void WellState::initSingleWell(const std::vector<double>& cellPressures,
     this->well_potentials_.add(well.name(), std::vector<double>(np, 0));
     const int num_perf_this_well = well_info->communication().sum(well_perf_data_[w].size());
     this->segment_state.add(well.name(), SegmentState{});
-    this->perfdata.add(well.name(), PerfData{static_cast<std::size_t>(num_perf_this_well), this->phase_usage_});
+    this->perfdata.add(well.name(), PerfData{static_cast<std::size_t>(num_perf_this_well), well.isInjector(), this->phase_usage_});
     this->bhp_.add(well.name(), 0.0);
     this->thp_.add(well.name(), 0.0);
     this->productivity_index_.add(well.name(), std::vector<double>(np, 0));
diff --git a/tests/test_wellstate.cpp b/tests/test_wellstate.cpp
index 437590fa8..eb8e921d1 100644
--- a/tests/test_wellstate.cpp
+++ b/tests/test_wellstate.cpp
@@ -545,9 +545,10 @@ GAS
 )";
     Opm::PhaseUsage pu = Opm::phaseUsageFromDeck(Opm::Parser{}.parseString(deck_string));
 
-    Opm::PerfData pd1(3,pu);
-    Opm::PerfData pd2(3,pu);
-    Opm::PerfData pd3(2,pu);
+    Opm::PerfData pd1(3, true, pu);
+    Opm::PerfData pd2(3, true, pu);
+    Opm::PerfData pd3(2, true, pu);
+    Opm::PerfData pd4(3, false, pu);
 
 
     for (std::size_t i = 0; i < 3; i++) {
@@ -565,6 +566,8 @@ GAS
     for (std::size_t i = 0; i < 3; i++) {
         BOOST_CHECK(pd1.pressure[i] == 10*(i+1));
     }
+
+    BOOST_CHECK(!pd1.try_assign(pd4));
 }