diff --git a/src/org/violetlib/vappearances/AppearancesCache.java b/src/org/violetlib/vappearances/AppearancesCache.java
index 132cf72..d07d1e9 100644
--- a/src/org/violetlib/vappearances/AppearancesCache.java
+++ b/src/org/violetlib/vappearances/AppearancesCache.java
@@ -15,7 +15,7 @@
 
 /* package private */ final class AppearancesCache
 {
-    private static final @NotNull Map<String,VAppearance> cache = new HashMap<>();
+    private final @NotNull Map<String,VAppearance> cache = new HashMap<>();
 
     public final static class Result
     {
diff --git a/src/org/violetlib/vappearances/SystemColorsCache.java b/src/org/violetlib/vappearances/SystemColorsCache.java
index d0e453f..e47a583 100644
--- a/src/org/violetlib/vappearances/SystemColorsCache.java
+++ b/src/org/violetlib/vappearances/SystemColorsCache.java
@@ -17,7 +17,7 @@
 
 /* package private */ final class SystemColorsCache
 {
-    private static final @NotNull Map<String,Map<String,Color>> cache = new HashMap<>();
+    private final @NotNull Map<String,Map<String,Color>> cache = new HashMap<>();
 
     public synchronized void clear()
     {