diff --git a/wdtk-rdf/src/main/java/org/wikidata/wdtk/rdf/values/StringValueConverter.java b/wdtk-rdf/src/main/java/org/wikidata/wdtk/rdf/values/StringValueConverter.java
index 9c72f346c..d1d1bd635 100644
--- a/wdtk-rdf/src/main/java/org/wikidata/wdtk/rdf/values/StringValueConverter.java
+++ b/wdtk-rdf/src/main/java/org/wikidata/wdtk/rdf/values/StringValueConverter.java
@@ -28,6 +28,9 @@
 import org.wikidata.wdtk.rdf.PropertyRegister;
 import org.wikidata.wdtk.rdf.RdfWriter;
 
+import java.net.URLEncoder;
+import java.nio.charset.StandardCharsets;
+
 public class StringValueConverter extends AbstractValueConverter<StringValue> {
 
 	public StringValueConverter(RdfWriter rdfWriter,
@@ -98,12 +101,12 @@ public Value getRdfValue(StringValue value,
 	 */
 	static String getCommonsFileUrl(String pageName) {
 		return "http://commons.wikimedia.org/wiki/File:"
-				+ pageName.replace(' ', '_');
+				+ URLEncoder.encode(pageName.replace(' ', '_'), StandardCharsets.UTF_8);
 	}
 
 	static String getCommonsDataUrl(String pageName) {
 		return "http://commons.wikimedia.org/data/main/"
-				+ pageName.replace(' ', '_');
+				+ URLEncoder.encode(pageName.replace(' ', '_'), StandardCharsets.UTF_8);
 	}
 
 }