diff --git a/structurizr-core/src/test/java/com/structurizr/view/ConfigurationTests.java b/structurizr-core/src/test/java/com/structurizr/view/ConfigurationTests.java
index ff3490c4..5a15e24d 100644
--- a/structurizr-core/src/test/java/com/structurizr/view/ConfigurationTests.java
+++ b/structurizr-core/src/test/java/com/structurizr/view/ConfigurationTests.java
@@ -36,14 +36,14 @@ void copyConfigurationFrom() {
     void setTheme_WithAUrl() {
         Configuration configuration = new Configuration();
         configuration.setTheme("https://example.com/theme.json");
-        assertEquals("https://example.com/theme.json", configuration.getTheme());
+        assertEquals("https://example.com/theme.json", configuration.getThemes()[0]);
     }
 
     @Test
     void setTheme_WithAUrlThatHasATrailingSpace() {
         Configuration configuration = new Configuration();
         configuration.setTheme("https://example.com/theme.json ");
-        assertEquals("https://example.com/theme.json", configuration.getTheme());
+        assertEquals("https://example.com/theme.json", configuration.getThemes()[0]);
     }
 
     @Test
@@ -58,14 +58,14 @@ void setTheme_ThrowsAnIllegalArgumentException_WhenAnInvalidUrlIsSpecified() {
     void setTheme_DoesNothing_WhenANullUrlIsSpecified() {
         Configuration configuration = new Configuration();
         configuration.setTheme(null);
-        assertNull(configuration.getTheme());
+        assertEquals(0, configuration.getThemes().length);
     }
 
     @Test
     void setTheme_DoesNothing_WhenAnEmptyUrlIsSpecified() {
         Configuration configuration = new Configuration();
         configuration.setTheme(" ");
-        assertNull(configuration.getTheme());
+        assertEquals(0, configuration.getThemes().length);
     }
 
 }
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