diff --git a/libs/kimath/include/md5_hash.h b/libs/kimath/include/md5_hash.h
index 56fa39786a..3eea52a8ad 100644
--- a/libs/kimath/include/md5_hash.h
+++ b/libs/kimath/include/md5_hash.h
@@ -32,8 +32,10 @@ public:
 
     /** @return Build a hexadecimal string from the 16 bytes of MD5_HASH
      *  Mainly for debug purposes.
+     * @param aCompactForm = false to generate a string with spaces between each byte (2 chars)
+     * = true to generate a string filled with 32 hexadecimal chars
      */
-    std::string Format();
+    std::string Format( bool aCompactForm = false );
 
 private:
     struct MD5_CTX {
diff --git a/libs/kimath/src/md5_hash.cpp b/libs/kimath/src/md5_hash.cpp
index db2f7c9f35..c8c1071859 100644
--- a/libs/kimath/src/md5_hash.cpp
+++ b/libs/kimath/src/md5_hash.cpp
@@ -90,7 +90,7 @@ bool MD5_HASH::operator!=( const MD5_HASH& aOther ) const
 }
 
 
-std::string MD5_HASH::Format()
+std::string MD5_HASH::Format( bool aCompactForm )
 {
     std::string data;
 
@@ -109,7 +109,9 @@ std::string MD5_HASH::Format()
 
          data += msb;
          data += lsb;
-         data += ' ';
+
+        if( !aCompactForm )
+            data += ' ';
     }
 
     return data;
diff --git a/pcbnew/specctra_import_export/specctra_export.cpp b/pcbnew/specctra_import_export/specctra_export.cpp
index 1815a4ac49..3faf11fe16 100644
--- a/pcbnew/specctra_import_export/specctra_export.cpp
+++ b/pcbnew/specctra_import_export/specctra_export.cpp
@@ -521,10 +521,12 @@ PADSTACK* SPECCTRA_DB::makePADSTACK( BOARD* aBoard, PAD* aPad )
             }
 
             // this string _must_ be unique for a given physical shape
-            snprintf( name, sizeof(name), "RoundRect%sPad_%.6gx%.6g_%.6g_um",
+            snprintf( name, sizeof(name), "RoundRect%sPad_%.6gx%.6g_%.6g_um_%f_%X",
                       uniqifier.c_str(),
                       IU2um( aPad->GetSize().x ),
-                      IU2um( aPad->GetSize().y ), IU2um( rradius ) );
+                      IU2um( aPad->GetSize().y ), IU2um( rradius ),
+                      doChamfer ? aPad->GetChamferRectRatio() : 0.0,
+                      doChamfer ? aPad->GetChamferPositions() : 0 );
 
             name[ sizeof(name) - 1 ] = 0;
 
@@ -573,11 +575,12 @@ PADSTACK* SPECCTRA_DB::makePADSTACK( BOARD* aBoard, PAD* aPad )
             }
 
             // this string _must_ be unique for a given physical shape, so try to make it unique
+            MD5_HASH hash  = pad_shape.GetHash();
             EDA_RECT rect = aPad->GetBoundingBox();
-            snprintf( name, sizeof(name), "Cust%sPad_%.6gx%.6g_%.6gx_%.6g_%d_um",
+            snprintf( name, sizeof(name), "Cust%sPad_%.6gx%.6g_%.6gx_%.6g_%d_um_%s",
                      uniqifier.c_str(), IU2um( aPad->GetSize().x ), IU2um( aPad->GetSize().y ),
                      IU2um( rect.GetWidth() ), IU2um( rect.GetHeight() ),
-                     (int)polygonal_shape.size() );
+                     (int)polygonal_shape.size(), hash.Format( true ).c_str() );
             name[ sizeof(name)-1 ] = 0;
 
             padstack->SetPadstackId( name );