diff --git a/src/db/db/dbNetlistSpiceReader.cc b/src/db/db/dbNetlistSpiceReader.cc
index 129fc248d..c019ef7c4 100644
--- a/src/db/db/dbNetlistSpiceReader.cc
+++ b/src/db/db/dbNetlistSpiceReader.cc
@@ -104,46 +104,66 @@ bool NetlistSpiceReaderDelegate::element (db::Circuit *circuit, const std::strin
   std::string cn = model;
   db::DeviceClass *cls = circuit->netlist ()->device_class_by_name (cn);
 
-  if (cls) {
+  if (element == "R") {
 
-    //  use given class
-
-  } else if (element == "R") {
-
-    if (cn.empty ()) {
-      cn = "RES";
+    if (cls) {
+      if (! dynamic_cast<db::DeviceClassResistor *>(cls)) {
+        error (tl::sprintf (tl::to_string (tr ("Class %s not a resistor device class as required by 'R' element")), cn));
+      }
+    } else {
+      if (cn.empty ()) {
+        cn = "RES";
+      }
+      cls = make_device_class<db::DeviceClassResistor> (circuit, cn);
     }
-    cls = make_device_class<db::DeviceClassResistor> (circuit, cn);
 
     //  Apply multiplier
     value /= mult;
 
   } else if (element == "L") {
 
-    if (cn.empty ()) {
-      cn = "IND";
+    if (cls) {
+      if (! dynamic_cast<db::DeviceClassInductor *>(cls)) {
+        error (tl::sprintf (tl::to_string (tr ("Class %s not a inductor device class as required by 'L' element")), cn));
+      }
+    } else {
+      if (cn.empty ()) {
+        cn = "IND";
+      }
+      cls = make_device_class<db::DeviceClassInductor> (circuit, cn);
     }
-    cls = make_device_class<db::DeviceClassInductor> (circuit, cn);
 
     //  Apply multiplier
     value /= mult;
 
   } else if (element == "C") {
 
-    if (cn.empty ()) {
-      cn = "CAP";
+    if (cls) {
+      if (! dynamic_cast<db::DeviceClassCapacitor *>(cls)) {
+        error (tl::sprintf (tl::to_string (tr ("Class %s not a capacitor device class as required by 'C' element")), cn));
+      }
+    } else {
+      if (cn.empty ()) {
+        cn = "CAP";
+      }
+      cls = make_device_class<db::DeviceClassCapacitor> (circuit, cn);
     }
-    cls = make_device_class<db::DeviceClassCapacitor> (circuit, cn);
 
     //  Apply multiplier
     value *= mult;
 
   } else if (element == "D") {
 
-    if (cn.empty ()) {
-      cn = "DIODE";
+    if (cls) {
+      if (! dynamic_cast<db::DeviceClassDiode *>(cls)) {
+        error (tl::sprintf (tl::to_string (tr ("Class %s not a diode device class as required by 'D' element")), cn));
+      }
+    } else {
+      if (cn.empty ()) {
+        cn = "DIODE";
+      }
+      cls = make_device_class<db::DeviceClassDiode> (circuit, cn);
     }
-    cls = make_device_class<db::DeviceClassDiode> (circuit, cn);
 
     //  Apply multiplier to "A"
     std::map<std::string, double>::iterator p;
@@ -154,18 +174,30 @@ bool NetlistSpiceReaderDelegate::element (db::Circuit *circuit, const std::strin
 
   } else if (element == "Q") {
 
-    if (nets.size () == 3) {
-      if (cn.empty ()) {
-        cn = "BJT3";
-      }
-      cls = make_device_class<db::DeviceClassBJT3Transistor> (circuit, cn);
-    } else if (nets.size () == 4) {
-      if (cn.empty ()) {
-        cn = "BJT4";
-      }
-      cls = make_device_class<db::DeviceClassBJT4Transistor> (circuit, cn);
-    } else {
+    if (nets.size () != 3 && nets.size () != 4) {
       error (tl::to_string (tr ("'Q' element needs to have 3 or 4 terminals")));
+    } else if (cls) {
+      if (nets.size () == 3) {
+        if (! dynamic_cast<db::DeviceClassBJT3Transistor *>(cls)) {
+          error (tl::sprintf (tl::to_string (tr ("Class %s not a 3-terminal BJT device class as required by 'Q' element")), cn));
+        }
+      } else {
+        if (! dynamic_cast<db::DeviceClassBJT4Transistor *>(cls)) {
+          error (tl::sprintf (tl::to_string (tr ("Class %s not a 4-terminal BJT device class as required by 'Q' element")), cn));
+        }
+      }
+    } else {
+      if (nets.size () == 3) {
+        if (cn.empty ()) {
+          cn = "BJT3";
+        }
+        cls = make_device_class<db::DeviceClassBJT3Transistor> (circuit, cn);
+      } else {
+        if (cn.empty ()) {
+          cn = "BJT4";
+        }
+        cls = make_device_class<db::DeviceClassBJT4Transistor> (circuit, cn);
+      }
     }
 
     //  Apply multiplier to "AE"
@@ -177,22 +209,28 @@ bool NetlistSpiceReaderDelegate::element (db::Circuit *circuit, const std::strin
 
   } else if (element == "M") {
 
-    if (nets.size () == 4) {
-      if (cn.empty ()) {
-        cn = "MOS4";
+    if (cls) {
+      if (! dynamic_cast<db::DeviceClassMOS4Transistor *>(cls)) {
+        error (tl::sprintf (tl::to_string (tr ("Class %s not a 4-terminal MOS device class as required by 'M' element")), cn));
       }
-      cls = make_device_class<db::DeviceClassMOS4Transistor> (circuit, cn);
-
-      //  Apply multiplier to "W"
-      std::map<std::string, double>::iterator p;
-      p = params.find ("W");
-      if (p != params.end ()) {
-        p->second *= mult;
-      }
-
     } else {
-      error (tl::to_string (tr ("'M' element needs to have 4 terminals")));
+      if (nets.size () == 4) {
+        if (cn.empty ()) {
+          cn = "MOS4";
+        }
+        cls = make_device_class<db::DeviceClassMOS4Transistor> (circuit, cn);
+      } else {
+        error (tl::to_string (tr ("'M' element needs to have 4 terminals")));
+      }
     }
+
+    //  Apply multiplier to "W"
+    std::map<std::string, double>::iterator p;
+    p = params.find ("W");
+    if (p != params.end ()) {
+      p->second *= mult;
+    }
+
   } else {
     error (tl::sprintf (tl::to_string (tr ("Not a known element type: '%s'")), element));
   }
diff --git a/src/db/unit_tests/dbNetlistReaderTests.cc b/src/db/unit_tests/dbNetlistReaderTests.cc
index 12f0a97f6..4e4779588 100644
--- a/src/db/unit_tests/dbNetlistReaderTests.cc
+++ b/src/db/unit_tests/dbNetlistReaderTests.cc
@@ -359,28 +359,75 @@ TEST(9_DeviceMultipliers)
 
   std::string path = tl::combine_path (tl::combine_path (tl::combine_path (tl::testsrc (), "testdata"), "algo"), "nreader9.cir");
 
-  db::NetlistSpiceReader reader;
-  tl::InputStream is (path);
-  reader.read (is, nl);
+  {
+    db::NetlistSpiceReader reader;
+    tl::InputStream is (path);
+    reader.read (is, nl);
 
-  std::string nl_string = nl.to_string ();
-  //  normalization of exponential representation:
-  nl_string = tl::replaced (nl_string, "e-009", "e-09");
+    std::string nl_string = nl.to_string ();
+    //  normalization of exponential representation:
+    nl_string = tl::replaced (nl_string, "e-009", "e-09");
 
-  EXPECT_EQ (nl_string,
-    "circuit .TOP ();\n"
-    "  device RES $1 (A='1',B='2') (R=850,L=0,W=0,A=0,P=0);\n"
-    "  device RES $2 (A='3',B='4') (R=1700,L=0,W=0,A=0,P=0);\n"
-    "  device NMOS $1 (S='1',G='2',D='3',B='4') (L=7,W=4,AS=0,AD=0,PS=0,PD=0);\n"
-    "  device PMOS $2 (S='1',G='2',D='3',B='4') (L=7,W=2,AS=0,AD=0,PS=0,PD=0);\n"
-    "  device CAP $1 (A='1',B='2') (C=2e-09,A=0,P=0);\n"
-    "  device CAP $2 (A='3',B='4') (C=1e-09,A=0,P=0);\n"
-    "  device DIODE $1 (A='1',C='2') (A=20,P=0);\n"
-    "  device DIODE $2 (A='3',C='4') (A=10,P=0);\n"
-    "  device BIP $1 (C='1',B='2',E='3',S='4') (AE=20,PE=0,AB=0,PB=0,AC=0,PC=0,NE=1);\n"
-    "  device BIP $2 (C='1',B='2',E='3',S='4') (AE=10,PE=0,AB=0,PB=0,AC=0,PC=0,NE=1);\n"
-    "end;\n"
-  );
+    EXPECT_EQ (nl_string,
+      "circuit .TOP ();\n"
+      "  device RES $1 (A='1',B='2') (R=850,L=0,W=0,A=0,P=0);\n"
+      "  device RES $2 (A='3',B='4') (R=1700,L=0,W=0,A=0,P=0);\n"
+      "  device RMODEL $3 (A='1',B='2') (R=850,L=0,W=0,A=0,P=0);\n"
+      "  device RMODEL $4 (A='3',B='4') (R=1700,L=0,W=0,A=0,P=0);\n"
+      "  device NMOS $1 (S='1',G='2',D='3',B='4') (L=7,W=4,AS=0,AD=0,PS=0,PD=0);\n"
+      "  device PMOS $2 (S='1',G='2',D='3',B='4') (L=7,W=2,AS=0,AD=0,PS=0,PD=0);\n"
+      "  device CAP $1 (A='1',B='2') (C=2e-09,A=0,P=0);\n"
+      "  device CAP $2 (A='3',B='4') (C=1e-09,A=0,P=0);\n"
+      "  device CMODEL $3 (A='1',B='2') (C=2e-09,A=0,P=0);\n"
+      "  device CMODEL $4 (A='3',B='4') (C=1e-09,A=0,P=0);\n"
+      "  device IND $1 (A='1',B='2') (L=5e-10);\n"
+      "  device IND $2 (A='3',B='4') (L=1e-09);\n"
+      "  device LMODEL $3 (A='1',B='2') (L=5e-10);\n"
+      "  device LMODEL $4 (A='3',B='4') (L=1e-09);\n"
+      "  device DIODE $1 (A='1',C='2') (A=20,P=0);\n"
+      "  device DIODE $2 (A='3',C='4') (A=10,P=0);\n"
+      "  device BIP $1 (C='1',B='2',E='3',S='4') (AE=20,PE=0,AB=0,PB=0,AC=0,PC=0,NE=1);\n"
+      "  device BIP $2 (C='1',B='2',E='3',S='4') (AE=10,PE=0,AB=0,PB=0,AC=0,PC=0,NE=1);\n"
+      "end;\n"
+    );
+  }
+
+  db::Circuit *top = nl.circuit_by_name (".TOP");
+  nl.remove_circuit (top);
+
+  //  read once again, this time with known classes (must not trigger issue-652)
+  {
+    db::NetlistSpiceReader reader;
+    tl::InputStream is (path);
+    reader.read (is, nl);
+
+    std::string nl_string = nl.to_string ();
+    //  normalization of exponential representation:
+    nl_string = tl::replaced (nl_string, "e-009", "e-09");
+
+    EXPECT_EQ (nl_string,
+      "circuit .TOP ();\n"
+      "  device RES $1 (A='1',B='2') (R=850,L=0,W=0,A=0,P=0);\n"
+      "  device RES $2 (A='3',B='4') (R=1700,L=0,W=0,A=0,P=0);\n"
+      "  device RMODEL $3 (A='1',B='2') (R=850,L=0,W=0,A=0,P=0);\n"
+      "  device RMODEL $4 (A='3',B='4') (R=1700,L=0,W=0,A=0,P=0);\n"
+      "  device NMOS $1 (S='1',G='2',D='3',B='4') (L=7,W=4,AS=0,AD=0,PS=0,PD=0);\n"
+      "  device PMOS $2 (S='1',G='2',D='3',B='4') (L=7,W=2,AS=0,AD=0,PS=0,PD=0);\n"
+      "  device CAP $1 (A='1',B='2') (C=2e-09,A=0,P=0);\n"
+      "  device CAP $2 (A='3',B='4') (C=1e-09,A=0,P=0);\n"
+      "  device CMODEL $3 (A='1',B='2') (C=2e-09,A=0,P=0);\n"
+      "  device CMODEL $4 (A='3',B='4') (C=1e-09,A=0,P=0);\n"
+      "  device IND $1 (A='1',B='2') (L=5e-10);\n"
+      "  device IND $2 (A='3',B='4') (L=1e-09);\n"
+      "  device LMODEL $3 (A='1',B='2') (L=5e-10);\n"
+      "  device LMODEL $4 (A='3',B='4') (L=1e-09);\n"
+      "  device DIODE $1 (A='1',C='2') (A=20,P=0);\n"
+      "  device DIODE $2 (A='3',C='4') (A=10,P=0);\n"
+      "  device BIP $1 (C='1',B='2',E='3',S='4') (AE=20,PE=0,AB=0,PB=0,AC=0,PC=0,NE=1);\n"
+      "  device BIP $2 (C='1',B='2',E='3',S='4') (AE=10,PE=0,AB=0,PB=0,AC=0,PC=0,NE=1);\n"
+      "end;\n"
+    );
+  }
 }
 
 TEST(10_SubcircuitsNoPins)
diff --git a/testdata/algo/nreader9.cir b/testdata/algo/nreader9.cir
index 302b7a0a2..e68e4bd20 100644
--- a/testdata/algo/nreader9.cir
+++ b/testdata/algo/nreader9.cir
@@ -1,10 +1,18 @@
 
 R$1 1 2 1.7k M=2
 R$2 3 4 1.7k
+R$3 1 2 1.7k RMODEL M=2
+R$4 3 4 1.7k RMODEL
 M$1 1 2 3 4 NMOS W=2u L=7u M=2
 M$2 1 2 3 4 PMOS W=2u L=7u 
 C$1 1 2 1e-9 M=2 
 C$2 3 4 1e-9 
+C$3 1 2 1e-9 CMODEL M=2 
+C$4 3 4 1e-9 CMODEL 
+L$1 1 2 1e-9 M=2 
+L$2 3 4 1e-9 
+L$3 1 2 1e-9 LMODEL M=2 
+L$4 3 4 1e-9 LMODEL 
 D$1 1 2 DIODE A=10P M=2 
 D$2 3 4 DIODE A=10P
 Q$1 1 2 3 4 BIP AE=10P M=2