diff --git a/ChangeLog b/ChangeLog
index a25a799..8731b08 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 mbed TLS ChangeLog (Sorted per branch, date)
 
+= mbed TLS x.x.x branch released xxxx-xx-xx
+
+Bugfix
+   * Fix spurious uninitialized variable warning in cmac.c. Fix independently
+     contributed by Brian J Murray and David Brown.
+
 = mbed TLS 2.7.2 branch released 2018-03-16
 
 Security
diff --git a/library/cmac.c b/library/cmac.c
index 9dbff90..a4a2106 100644
--- a/library/cmac.c
+++ b/library/cmac.c
@@ -771,7 +771,7 @@
                               int block_size,
                               int num_tests )
 {
-    int i, ret;
+    int i, ret = 0;
     mbedtls_cipher_context_t ctx;
     const mbedtls_cipher_info_t *cipher_info;
     unsigned char K1[MBEDTLS_CIPHER_BLKSIZE_MAX];
@@ -853,7 +853,7 @@
                                  int num_tests )
 {
     const mbedtls_cipher_info_t *cipher_info;
-    int i, ret;
+    int i, ret = 0;
     unsigned char output[MBEDTLS_CIPHER_BLKSIZE_MAX];
 
     cipher_info = mbedtls_cipher_info_from_type( cipher_type );