diff --git a/include/net/checksum.h b/include/net/checksum.h
index 10a16b5bd1c7..abffc64e7300 100644
--- a/include/net/checksum.h
+++ b/include/net/checksum.h
@@ -120,6 +120,11 @@ static inline __wsum csum_partial_ext(const void *buff, int len, __wsum sum)
 
 #define CSUM_MANGLED_0 ((__force __sum16)0xffff)
 
+static inline void csum_replace_by_diff(__sum16 *sum, __wsum diff)
+{
+	*sum = csum_fold(csum_add(diff, ~csum_unfold(*sum)));
+}
+
 static inline void csum_replace4(__sum16 *sum, __be32 from, __be32 to)
 {
 	__wsum tmp = csum_sub(~csum_unfold(*sum), (__force __wsum)from);
diff --git a/net/core/filter.c b/net/core/filter.c
index 69f4ffc0a282..356a251657a5 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -1447,6 +1447,12 @@ static u64 bpf_l3_csum_replace(u64 r1, u64 r2, u64 from, u64 to, u64 flags)
 		return -EFAULT;
 
 	switch (flags & BPF_F_HDR_FIELD_MASK) {
+	case 0:
+		if (unlikely(from != 0))
+			return -EINVAL;
+
+		csum_replace_by_diff(ptr, to);
+		break;
 	case 2:
 		csum_replace2(ptr, from, to);
 		break;