diff --git a/dub.sdl b/dub.sdl
index 1dcfb87..462843c 100644
--- a/dub.sdl
+++ b/dub.sdl
@@ -4,7 +4,7 @@ authors "Sönke Ludwig"
 copyright "Copyright © 2016-2020, Sönke Ludwig"
 license "MIT"
 
-dependency "eventcore" version="~>0.8.43"
+dependency "eventcore" version="~>0.9.0"
 dependency "stdx-allocator" version="~>2.77.0"
 
 targetName "vibe_core"
diff --git a/source/vibe/core/file.d b/source/vibe/core/file.d
index d679b22..697f439 100644
--- a/source/vibe/core/file.d
+++ b/source/vibe/core/file.d
@@ -190,16 +190,21 @@ void moveFile(NativePath from, NativePath to, bool copy_fallback = false)
 /// ditto
 void moveFile(string from, string to, bool copy_fallback = false)
 {
-	if (!copy_fallback) {
-		std.file.rename(from, to);
-	} else {
+	auto fail = performInWorker((string from, string to) {
 		try {
 			std.file.rename(from, to);
-		} catch (FileException e) {
-			copyFile(from, to);
-			std.file.remove(from);
+		} catch (Exception e) {
+			return e.msg.length ? e.msg : "Failed to move file.";
 		}
-	}
+		return null;
+	}, from, to);
+
+	if (!fail.length) return;
+
+	if (!copy_fallback) throw new Exception(fail);
+
+	copyFile(from, to);
+	removeFile(from);
 }
 
 /**
@@ -236,6 +241,7 @@ void copyFile(NativePath from, NativePath to, bool overwrite = false)
 		enforce(overwrite || !existsFile(to), "Destination file already exists.");
 		auto dst = openFile(to, FileMode.createTrunc);
 		scope(exit) dst.close();
+		dst.truncate(src.size);
 		dst.write(src);
 	}
 
@@ -267,7 +273,16 @@ void removeFile(NativePath path)
 /// ditto
 void removeFile(string path)
 {
-	std.file.remove(path);
+	auto fail = performInWorker((string path) {
+		try {
+			std.file.remove(path);
+		} catch (Exception e) {
+			return e.msg.length ? e.msg : "Failed to delete file.";
+		}
+		return null;
+	}, path);
+
+	if (fail.length) throw new Exception(fail);
 }
 
 /**
@@ -567,12 +582,18 @@ struct FileStream {
 	/// Closes the file handle.
 	void close()
 	{
-		if (m_fd != FileFD.init) {
-			eventDriver.files.close(m_fd); // FIXME: may leave dangling references!
-			releaseHandle!"files"(m_fd, m_ctx.driver);
-			m_fd = FileFD.init;
-			m_ctx = null;
-		}
+		if (m_fd == FileFD.invalid) return;
+		if (!eventDriver.files.isValid(m_fd)) return;
+
+		auto res = asyncAwaitUninterruptible!(FileCloseCallback,
+			cb => eventDriver.files.close(m_fd, cb)
+		);
+		releaseHandle!"files"(m_fd, m_ctx.driver);
+		m_fd = FileFD.invalid;
+		m_ctx = null;
+
+		if (res[1] != CloseStatus.ok)
+			throw new Exception("Failed to close file");
 	}
 
 	@property bool empty() const { assert(this.readable); return ctx.ptr >= ctx.size; }
diff --git a/source/vibe/core/internal/release.d b/source/vibe/core/internal/release.d
index 33dac9c..a99a428 100644
--- a/source/vibe/core/internal/release.d
+++ b/source/vibe/core/internal/release.d
@@ -1,6 +1,7 @@
 module vibe.core.internal.release;
 
 import eventcore.core;
+import std.stdint : intptr_t;
 
 /// Release a handle in a thread-safe way
 void releaseHandle(string subsys, H)(H handle, shared(NativeEventDriver) drv)
@@ -19,8 +20,8 @@ void releaseHandle(string subsys, H)(H handle, shared(NativeEventDriver) drv)
 
 		// in case the destructor was called from a foreign thread,
 		// perform the release in the owner thread
-		drv.core.runInOwnerThread((h) {
-			__traits(getMember, eventDriver, subsys).releaseRef(cast(H)h);
-		}, cast(size_t)handle);
+		drv.core.runInOwnerThread((H handle) {
+			__traits(getMember, eventDriver, subsys).releaseRef(handle);
+		}, handle);
 	}
 }
diff --git a/source/vibe/core/process.d b/source/vibe/core/process.d
index aa3b20b..0d0d4f8 100644
--- a/source/vibe/core/process.d
+++ b/source/vibe/core/process.d
@@ -453,7 +453,14 @@ struct PipeInputStream {
     */
     void close()
     nothrow {
-        eventDriver.pipes.close(m_pipe);
+		if (m_pipe == PipeFD.invalid) return;
+
+		asyncAwaitUninterruptible!(PipeCloseCallback,
+			cb => eventDriver.pipes.close(m_pipe, cb)
+		);
+
+		eventDriver.pipes.releaseRef(m_pipe);
+		m_pipe = PipeFD.invalid;
     }
 }
 
@@ -528,7 +535,14 @@ struct PipeOutputStream {
     */
     void close()
     nothrow {
-        eventDriver.pipes.close(m_pipe);
+		if (m_pipe == PipeFD.invalid) return;
+
+		asyncAwaitUninterruptible!(PipeCloseCallback,
+			cb => eventDriver.pipes.close(m_pipe, cb)
+		);
+
+		eventDriver.pipes.releaseRef(m_pipe);
+		m_pipe = PipeFD.invalid;
     }
 }