diff --git a/Makefile b/Makefile
index 984e9a0..2349e50 100644
--- a/Makefile
+++ b/Makefile
@@ -43,7 +43,7 @@ Assembly.o: kthread.h
 CommandLines.o: CommandLines.h ketopt.h
 Correct.o: Correct.h Hash_Table.h htab.h Process_Read.h Overlaps.h kvec.h
 Correct.o: kdq.h CommandLines.h Levenshtein_distance.h POA.h Assembly.h
-Correct.o: ksw2.h
+Correct.o: ksw2.h ksort.h
 Hash_Table.o: Hash_Table.h htab.h Process_Read.h Overlaps.h kvec.h kdq.h
 Hash_Table.o: CommandLines.h ksort.h
 Levenshtein_distance.o: Levenshtein_distance.h
diff --git a/README.md b/README.md
index ac76766..5dd7a5a 100644
--- a/README.md
+++ b/README.md
@@ -192,4 +192,8 @@ page](https://github.com/chhylp123/hifiasm/issues).
 
 ## Limitations
 
-1. Purging haplotig duplications may introduce misassemblies.
\ No newline at end of file
+1. Purging haplotig duplications may introduce misassemblies.
+
+## Citation
+
+Cheng, H., Concepcion, G.T., Feng, X., Zhang, H., Li H. Haplotype-resolved de novo assembly using phased assembly graphs with hifiasm. Nat Methods 18, 170–175 (2021). https://doi.org/10.1038/s41592-020-01056-5