diff --git a/kernel/dtable.cpp b/kernel/dtable.cpp
index 7dc56da2..836f9966 100644
--- a/kernel/dtable.cpp
+++ b/kernel/dtable.cpp
@@ -231,9 +231,7 @@ int DescriptorTable::Copy(int from, int to, int flags)
 	if ( flags & ~__FD_ALLOWED_FLAGS )
 		return errno = EINVAL, -1;
 	ScopedLock lock(&dtablelock);
-	if ( from < 0 || to < 0 )
-		return errno = EINVAL, -1;
-	if ( !IsGoodEntry(from) )
+	if ( !IsGoodEntry(from) || to < 0 )
 		return errno = EBADF, -1;
 	if ( from == to )
 		return errno = EINVAL, -1;
diff --git a/kernel/io.cpp b/kernel/io.cpp
index bf05903d..61b537ba 100644
--- a/kernel/io.cpp
+++ b/kernel/io.cpp
@@ -154,8 +154,6 @@ int sys_dup3(int oldfd, int newfd, int flags)
 
 int sys_dup2(int oldfd, int newfd)
 {
-	if ( oldfd < 0 || newfd < 0 )
-		return errno = EINVAL, -1;
 	int ret = sys_dup3(oldfd, newfd, 0);
 	if ( ret < 0 && errno == EINVAL )
 		return errno = 0, newfd;