diff --git a/src/system/libroot/posix/sys/uio.c b/src/system/libroot/posix/sys/uio.c
index 77eb2e1d7f..2d58ef1fbc 100644
--- a/src/system/libroot/posix/sys/uio.c
+++ b/src/system/libroot/posix/sys/uio.c
@@ -30,7 +30,12 @@ readv(int fd, const struct iovec *vecs, size_t count)
 ssize_t
 readv_pos(int fd, off_t pos, const struct iovec *vecs, size_t count)
 {
-	ssize_t bytes = _kern_readv(fd, pos, vecs, count);
+	ssize_t bytes;
+	if (pos < 0) {
+		errno = B_BAD_VALUE;
+		return -1;
+	}
+	bytes = _kern_readv(fd, pos, vecs, count);
 
 	RETURN_AND_SET_ERRNO(bytes);
 }
@@ -48,7 +53,12 @@ writev(int fd, const struct iovec *vecs, size_t count)
 ssize_t
 writev_pos(int fd, off_t pos, const struct iovec *vecs, size_t count)
 {
-	ssize_t bytes = _kern_writev(fd, pos, vecs, count);
+	ssize_t bytes;
+	if (pos < 0) {
+		errno = B_BAD_VALUE;
+		return -1;
+	}
+	bytes = _kern_writev(fd, pos, vecs, count);
 
 	RETURN_AND_SET_ERRNO(bytes);
 }
diff --git a/src/system/libroot/posix/unistd/read.c b/src/system/libroot/posix/unistd/read.c
index 60dcec7c81..06b63144ec 100644
--- a/src/system/libroot/posix/unistd/read.c
+++ b/src/system/libroot/posix/unistd/read.c
@@ -34,7 +34,12 @@ read(int fd, void *buffer, size_t bufferSize)
 ssize_t
 read_pos(int fd, off_t pos, void *buffer, size_t bufferSize)
 {
-	ssize_t status = _kern_read(fd, pos, buffer, bufferSize);
+	ssize_t status;
+	if (pos < 0) {
+		errno = B_BAD_VALUE;
+		return -1;
+	}
+	status = _kern_read(fd, pos, buffer, bufferSize);
 
 	RETURN_AND_SET_ERRNO(status);
 }
@@ -43,7 +48,12 @@ read_pos(int fd, off_t pos, void *buffer, size_t bufferSize)
 ssize_t
 pread(int fd, void *buffer, size_t bufferSize, off_t pos)
 {
-	ssize_t status = _kern_read(fd, pos, buffer, bufferSize);
+	ssize_t status;
+	if (pos < 0) {
+		errno = B_BAD_VALUE;
+		return -1;
+	}
+	status = _kern_read(fd, pos, buffer, bufferSize);
 
 	RETURN_AND_SET_ERRNO(status);
 }
diff --git a/src/system/libroot/posix/unistd/write.c b/src/system/libroot/posix/unistd/write.c
index 9d0c54a044..b881e4c7a9 100644
--- a/src/system/libroot/posix/unistd/write.c
+++ b/src/system/libroot/posix/unistd/write.c
@@ -32,7 +32,12 @@ write(int fd, void const *buffer, size_t bufferSize)
 ssize_t
 write_pos(int fd, off_t pos, const void *buffer, size_t bufferSize)
 {
-	int status = _kern_write(fd, pos, buffer, bufferSize);
+	ssize_t status;
+	if (pos < 0) {
+		errno = B_BAD_VALUE;
+		return -1;
+	}
+	status = _kern_write(fd, pos, buffer, bufferSize);
 
 	RETURN_AND_SET_ERRNO(status);
 }
@@ -41,7 +46,12 @@ write_pos(int fd, off_t pos, const void *buffer, size_t bufferSize)
 ssize_t
 pwrite(int fd, const void *buffer, size_t bufferSize, off_t pos)
 {
-	int status = _kern_write(fd, pos, buffer, bufferSize);
+	ssize_t status;
+	if (pos < 0) {
+		errno = B_BAD_VALUE;
+		return -1;
+	}
+	status = _kern_write(fd, pos, buffer, bufferSize);
 
 	RETURN_AND_SET_ERRNO(status);
 }