diff --git a/test/eu/simstadt/regionchooser/test/RegionExtractorTests.java b/test/eu/simstadt/regionchooser/test/RegionExtractorTests.java
index b73b7204568c8d97e82c0115cea7fd9222296c35..db9d5eddc4a929c247de187882770732b035f5df 100644
--- a/test/eu/simstadt/regionchooser/test/RegionExtractorTests.java
+++ b/test/eu/simstadt/regionchooser/test/RegionExtractorTests.java
@@ -4,14 +4,22 @@
 import static org.junit.Assert.assertTrue;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 import org.junit.Test;
 import eu.simstadt.regionchooser.RegionExtractor;
 
 
 public class RegionExtractorTests
 {
-	public static int countSubstring(String str, String subStr) {
-		return (str.length() - str.replace(subStr, "").length()) / subStr.length();
+	public static int countRegexMatches(String str, String subStr) {
+		Pattern pattern = Pattern.compile(subStr);
+		Matcher matcher = pattern.matcher(str);
+		int count = 0;
+		while (matcher.find()) {
+			count++;
+		}
+		return count;
 	}
 
 	@Test
@@ -21,7 +29,7 @@ public void testExtract3BuildingsFromGSK3Model() throws Throwable {
 		Path repo = Paths.get("../TestRepository");
 		Path citygmlPath = repo.resolve("Gruenbuehl.proj\\20140218_Gruenbuehl_LOD2.gml");
 		String churchGMLString = RegionExtractor.selectRegionDirectlyFromCityGML(citygmlPath, wktPolygon).toString();
-		assertEquals(countSubstring(churchGMLString, "<core:cityObjectMember"), 3);
+		assertEquals(countRegexMatches(churchGMLString, "<(core:)?cityObjectMember"), 3);
 		assertTrue(churchGMLString.contains("Donaustr"));
 		assertTrue(churchGMLString.contains("DEBW_LOD2_203056"));
 		assertTrue(churchGMLString.contains("DEBW_LOD2_2869"));