diff --git a/sampler/src/main/java/atlantafx/sampler/theme/CSSFragment.java b/sampler/src/main/java/atlantafx/sampler/theme/CSSFragment.java
index 6cd7b7a..bf3fe93 100644
--- a/sampler/src/main/java/atlantafx/sampler/theme/CSSFragment.java
+++ b/sampler/src/main/java/atlantafx/sampler/theme/CSSFragment.java
@@ -3,10 +3,11 @@ package atlantafx.sampler.theme;
 
 import javafx.scene.layout.Region;
 
-import java.nio.charset.StandardCharsets;
 import java.util.Base64;
 import java.util.Objects;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
+
 public final class CSSFragment {
 
     private static final String DATA_URI_PREFIX = "data:base64,";
@@ -51,6 +52,6 @@ public final class CSSFragment {
     }
 
     public String toDataURI() {
-        return DATA_URI_PREFIX + new String(Base64.getEncoder().encode(css.getBytes()), StandardCharsets.UTF_8);
+        return DATA_URI_PREFIX + new String(Base64.getEncoder().encode(css.getBytes(UTF_8)), UTF_8);
     }
 }
diff --git a/sampler/src/main/java/atlantafx/sampler/theme/SamplerTheme.java b/sampler/src/main/java/atlantafx/sampler/theme/SamplerTheme.java
index 6aff0b3..562d4f8 100644
--- a/sampler/src/main/java/atlantafx/sampler/theme/SamplerTheme.java
+++ b/sampler/src/main/java/atlantafx/sampler/theme/SamplerTheme.java
@@ -106,7 +106,7 @@ public final class SamplerTheme implements Theme {
         // classpath resources are static, no need to parse project theme more than once
         if (colors != null) { return colors; }
 
-        try (var br = new BufferedReader(new InputStreamReader(file.getInputStream()))) {
+        try (var br = new BufferedReader(new InputStreamReader(file.getInputStream(), UTF_8))) {
             colors = parseColors(br);
         }