diff --git a/src/cryfs_lib/CryFuse.cpp b/src/cryfs_lib/CryFuse.cpp
index f6ba1dad..169090cb 100644
--- a/src/cryfs_lib/CryFuse.cpp
+++ b/src/cryfs_lib/CryFuse.cpp
@@ -156,14 +156,12 @@ int CryFuse::fsyncdir(const char *path, int datasync, fuse_file_info *fileinfo)
   return 0;
 }
 
-void* CryFuse::init(fuse_conn_info *conn) {
+void CryFuse::init(fuse_conn_info *conn) {
   UNUSED(conn);
   printf("Called non-implemented init()\n");
-  return this;
 }
 
-void CryFuse::destroy(void *userdata) {
-  UNUSED(userdata);
+void CryFuse::destroy() {
   printf("Called non-implemented destroy()\n");
 }
 
diff --git a/src/cryfs_lib/CryFuse.h b/src/cryfs_lib/CryFuse.h
index 2196ad1f..8f3d109d 100644
--- a/src/cryfs_lib/CryFuse.h
+++ b/src/cryfs_lib/CryFuse.h
@@ -34,8 +34,8 @@ public:
   int readdir(const char *path, void *buf, fuse_fill_dir_t filler, off_t offset, fuse_file_info *fileinfo) override;
   int releasedir(const char *path, fuse_file_info *fileinfo) override;
   int fsyncdir(const char *path, int datasync, fuse_file_info *fileinfo) override;
-  void* init(fuse_conn_info *conn) override;
-  void destroy(void *userdata) override;
+  void init(fuse_conn_info *conn) override;
+  void destroy() override;
   int access(const char *path, int mask) override;
   int create(const char *path, mode_t mode, fuse_file_info *fileinfo) override;
 };
diff --git a/src/cryfs_lib/fusepp/Fuse.cpp b/src/cryfs_lib/fusepp/Fuse.cpp
index 71d64be7..5580ed1c 100644
--- a/src/cryfs_lib/fusepp/Fuse.cpp
+++ b/src/cryfs_lib/fusepp/Fuse.cpp
@@ -1,5 +1,6 @@
 #include "../fusepp/Fuse.h"
 #include <memory>
+#include <cassert>
 
 using std::unique_ptr;
 using std::make_unique;
@@ -120,11 +121,15 @@ int fsyncdir(const char *path, int datasync, fuse_file_info *fileinfo) {
 }
 
 void* init(fuse_conn_info *conn) {
-  return FUSE_OBJ->init(conn);
+  auto f = FUSE_OBJ;
+  f->init(conn);
+  return f;
 }
 
 void destroy(void *userdata) {
-  return FUSE_OBJ->destroy(userdata);
+  auto f = FUSE_OBJ;
+  assert(userdata == f);
+  f->destroy();
 }
 
 int access(const char *path, int mask) {
diff --git a/src/cryfs_lib/fusepp/Fuse.h b/src/cryfs_lib/fusepp/Fuse.h
index d18f3d5b..cd52ab11 100644
--- a/src/cryfs_lib/fusepp/Fuse.h
+++ b/src/cryfs_lib/fusepp/Fuse.h
@@ -44,8 +44,8 @@ public:
 	virtual int readdir(const char *path, void *buf, fuse_fill_dir_t filler, off_t offset, fuse_file_info *fileinfo) = 0;
 	virtual int releasedir(const char *path, fuse_file_info *fileinfo) = 0;
 	virtual int fsyncdir(const char *path, int datasync, fuse_file_info *fileinfo) = 0;
-	virtual void* init(fuse_conn_info *conn) = 0;
-	virtual void destroy(void *userdata) = 0;
+	virtual void init(fuse_conn_info *conn) = 0;
+	virtual void destroy() = 0;
 	virtual int access(const char *path, int mask) = 0;
 	virtual int create(const char *path, mode_t mode, fuse_file_info *fileinfo) = 0;
 };