diff --git a/src/db/db/dbNetlistSpiceReader.cc b/src/db/db/dbNetlistSpiceReader.cc
index c54a7e352..dff5050cc 100644
--- a/src/db/db/dbNetlistSpiceReader.cc
+++ b/src/db/db/dbNetlistSpiceReader.cc
@@ -254,6 +254,7 @@ void NetlistSpiceReader::read (tl::InputStream &stream, db::Netlist &netlist)
   mp_circuit = 0;
   mp_nets_by_name.reset (0);
   m_global_nets.clear ();
+  m_circuits_read.clear ();
 
   try {
 
@@ -891,11 +892,16 @@ void NetlistSpiceReader::read_circuit (tl::Extractor &ex, const std::string &nc)
   } else {
 
     if (cc->pin_count () != nn.size () + m_global_nets.size ()) {
-      error (tl::sprintf (tl::to_string (tr ("Pin count mismatch between implicit (through call) and explicit circuit definition: %d expected, got %d")), int (cc->pin_count ()), int (nn.size ())));
+      error (tl::sprintf (tl::to_string (tr ("Pin count mismatch between implicit (through call) and explicit circuit definition: %d expected, got %d in circuit %s")), int (cc->pin_count ()), int (nn.size ()), nc));
     }
 
   }
 
+  if (m_circuits_read.find (cc) != m_circuits_read.end ()) {
+    error (tl::sprintf (tl::to_string (tr ("Redefinition of circuit %s")), nc));
+  }
+  m_circuits_read.insert (cc);
+
   std::auto_ptr<std::map<std::string, db::Net *> > n2n (mp_nets_by_name.release ());
   mp_nets_by_name.reset (0);
 
diff --git a/src/db/db/dbNetlistSpiceReader.h b/src/db/db/dbNetlistSpiceReader.h
index 95eca62e2..ddf5eecea 100644
--- a/src/db/db/dbNetlistSpiceReader.h
+++ b/src/db/db/dbNetlistSpiceReader.h
@@ -28,6 +28,8 @@
 #include "tlStream.h"
 
 #include <string>
+#include <set>
+#include <map>
 #include <memory>
 
 namespace db
@@ -129,6 +131,7 @@ private:
   std::string m_stored_line;
   std::map<std::string, bool> m_captured;
   std::vector<std::string> m_global_nets;
+  std::set<const db::Circuit *> m_circuits_read;
 
   void push_stream (const std::string &path);
   void pop_stream ();
diff --git a/src/db/unit_tests/dbNetlistReaderTests.cc b/src/db/unit_tests/dbNetlistReaderTests.cc
index 98a6b3491..dc4d40d41 100644
--- a/src/db/unit_tests/dbNetlistReaderTests.cc
+++ b/src/db/unit_tests/dbNetlistReaderTests.cc
@@ -384,3 +384,21 @@ TEST(10_SubcircuitsNoPins)
   );
 }
 
+TEST(11_ErrorOnCircuitRedefinition)
+{
+  db::Netlist nl;
+
+  std::string path = tl::combine_path (tl::combine_path (tl::combine_path (tl::testsrc (), "testdata"), "algo"), "nreader11.cir");
+
+  std::string msg;
+  try {
+    db::NetlistSpiceReader reader;
+    tl::InputStream is (path);
+    reader.read (is, nl);
+  } catch (tl::Exception &ex) {
+    msg = ex.msg ();
+  }
+
+  EXPECT_EQ (tl::replaced (msg, path, "?"), "Redefinition of circuit SUBCKT in ?, line 20");
+}
+
diff --git a/testdata/algo/nreader11.cir b/testdata/algo/nreader11.cir
new file mode 100644
index 000000000..2b334a8d2
--- /dev/null
+++ b/testdata/algo/nreader11.cir
@@ -0,0 +1,22 @@
+* written by unit test
+
+* cell SUBCKT
+* pin 
+* pin A
+* pin V42
+* pin Z
+* pin gnd
+* pin gnd
+.SUBCKT SUBCKT \$1 A[5]<1> V42\x28\x25\x29 Z gnd gnd$1
+XD_$1 V42\x28\x25\x29 \$3 Z \$1 HVPMOS PARAMS: L=0.2 W=1 AS=0.18 AD=0.18
++ PS=2.16 PD=2.16
+* device instance $2 r0 *1 0,0 HVPMOS
+XD_$2 V42\x28\x25\x29 A[5]<1> \$3 \$1 HVPMOS PARAMS: L=0.2 W=1 AS=0.18 AD=0.18
++ PS=2.16 PD=2.16
+XD_$3 gnd \$3 gnd gnd$1 HVNMOS PARAMS: L=1.13 W=2.12 PS=6 PD=6 AS=0 AD=0
+XD_$4 gnd \$3 Z gnd$1 HVNMOS PARAMS: L=0.4 W=0.4 PS=1.16 PD=1.16 AS=0.19 AD=0.19
+XD_$5 gnd A[5]<1> \$3 gnd$1 HVNMOS PARAMS: L=0.4 W=0.4 PS=1.76 PD=1.76 AS=0.19 AD=0.19
+.ENDS SUBCKT
+.SUBCKT SUBCKT \$1 A[5]<1> V42\x28\x25\x29 Z gnd gnd$1
+XD_$13 gnd \$3 gnd gnd$1 HVNMOS PARAMS: L=1.13 W=2.12 PS=6 PD=6 AS=0 AD=0
+.ENDS SUBCKT