Index: src/main/java/info/magnolia/module/data/setup/DataModuleVersionHandler.java
===================================================================
--- src/main/java/info/magnolia/module/data/setup/DataModuleVersionHandler.java	(revision 33423)
+++ src/main/java/info/magnolia/module/data/setup/DataModuleVersionHandler.java	(revision 33430)
@@ -44,7 +44,6 @@
 import info.magnolia.module.ModuleRegistry;
 import info.magnolia.module.admininterface.setup.AddMainMenuItemTask;
 import info.magnolia.module.admininterface.setup.AddSubMenuItemTask;
-import info.magnolia.module.cache.RegisterWorkspaceForCacheFlushingTask;
 import info.magnolia.module.data.DataConsts;
 import info.magnolia.module.data.trees.WorkflowDataAdminTreeConfig;
 import info.magnolia.module.delta.AbstractRepositoryTask;
@@ -110,7 +109,14 @@
             }
         }));
         // This task can't be 1.2.2 as 1.2.2 depend on Magnolia 3.6.1 while the task was introduced later
-        register(DeltaBuilder.update("1.2.3", "").addTask(new RegisterWorkspaceForCacheFlushingTask("data")));
+        try {
+            register(DeltaBuilder.update("1.2.3", "").addTask(
+                new info.magnolia.module.cache.RegisterWorkspaceForCacheFlushingTask("data")));
+        }
+        catch (Throwable e) {
+            // silently ignore, cache module doesn't need to be available
+        }
+        
         register(DeltaBuilder.update("1.3.1", "")
                 .addTask(new ArrayDelegateTask("Data Importer", "Enables data importer for each data type.",
                         new CreateNodePathTask("", "", ContentRepository.CONFIG, "/modules/data/commands/data"),
@@ -210,7 +216,13 @@
                 "MgnlAdminCentral.showTree('config','/modules/data/dialogs')",
                 "/.resources/icons/16/gears.gif"
         ));
-        tasks.add(new RegisterWorkspaceForCacheFlushingTask("data"));
+        
+        try {
+            tasks.add(new info.magnolia.module.cache.RegisterWorkspaceForCacheFlushingTask("data"));
+        }
+        catch (Throwable e) {
+            // silently ignore, cache module doesn't need to be available
+        }
         return tasks;
     }
 
Index: src/main/resources/META-INF/magnolia/data.xml
===================================================================
--- src/main/resources/META-INF/magnolia/data.xml	(revision 33423)
+++ src/main/resources/META-INF/magnolia/data.xml	(revision 33430)
@@ -23,6 +23,7 @@
     <dependency>
       <name>cache</name>
       <version>4.2/*</version>
+      <optional>true</optional>
     </dependency>
   </dependencies>
   <repositories>