diff --git a/src/OpenMesh/Core/IO/writer/STLWriter.cc b/src/OpenMesh/Core/IO/writer/STLWriter.cc
index d8ba8443..3040ce66 100644
--- a/src/OpenMesh/Core/IO/writer/STLWriter.cc
+++ b/src/OpenMesh/Core/IO/writer/STLWriter.cc
@@ -166,7 +166,7 @@ write_stla(const std::string& _filename, BaseExporter& _be, Options /* _opt */)
 
 
   // header
-  fprintf(out, "solid\n");
+  fprintf(out, "solid \n");
 
 
   // write face set
@@ -220,7 +220,7 @@ write_stla(std::ostream& _out, BaseExporter& _be, Options /* _opt */, std::strea
 
 
   // header
-  _out << "solid\n";
+  _out << "solid \n";
 
 
   // write face set