diff --git a/library/ctr_drbg.c b/library/ctr_drbg.c
index c2310cb579..ff532a0134 100644
--- a/library/ctr_drbg.c
+++ b/library/ctr_drbg.c
@@ -19,7 +19,7 @@
  *  This file is part of mbed TLS (https://tls.mbed.org)
  */
 /*
- *  The NIST SP 800-90 DRBGs are described in the following publucation.
+ *  The NIST SP 800-90 DRBGs are described in the following publication.
  *
  *  http://csrc.nist.gov/publications/nistpubs/800-90/SP800-90revised_March2007.pdf
  */