diff --git a/converter-sbml/src/main/java/lcsb/mapviewer/converter/model/sbml/species/SbmlSpeciesParser.java b/converter-sbml/src/main/java/lcsb/mapviewer/converter/model/sbml/species/SbmlSpeciesParser.java
index 5df2e8166dfb44d4fcf2362e05d1738342be3210..c17c23765e6b96ef4e29f3a242395b22d58f82b5 100644
--- a/converter-sbml/src/main/java/lcsb/mapviewer/converter/model/sbml/species/SbmlSpeciesParser.java
+++ b/converter-sbml/src/main/java/lcsb/mapviewer/converter/model/sbml/species/SbmlSpeciesParser.java
@@ -106,7 +106,7 @@ public class SbmlSpeciesParser extends SbmlElementParser<org.sbml.jsbml.Species>
   protected void applyStyleToElement(Element elementWithLayout, LocalStyle style) {
     super.applyStyleToElement(elementWithLayout, style);
     Species specisWithLayout = (Species) elementWithLayout;
-    if (style.getGroup().getStrokeWidth() != null) {
+    if (style.getGroup().isSetStrokeWidth()) {
       specisWithLayout.setLineWidth(style.getGroup().getStrokeWidth());
     }
   }