diff --git a/include/mbedtls/error.h b/include/mbedtls/error.h
index 27420ce4fc..8b2b9ea580 100644
--- a/include/mbedtls/error.h
+++ b/include/mbedtls/error.h
@@ -56,7 +56,7 @@
  * Module   Nr  Codes assigned
  * ERROR     2  0x006E          0x0001
  * MPI       7  0x0002-0x0010
- * GCM       3  0x0012-0x0014   0x0013-0x0013
+ * GCM       3  0x0012-0x0016   0x0013-0x0013
  * THREADING 3  0x001A-0x001E
  * AES       5  0x0020-0x0022   0x0021-0x0025
  * CAMELLIA  3  0x0024-0x0026   0x0027-0x0027
diff --git a/include/mbedtls/gcm.h b/include/mbedtls/gcm.h
index a4de9191d8..7dc9dfb8ec 100644
--- a/include/mbedtls/gcm.h
+++ b/include/mbedtls/gcm.h
@@ -46,7 +46,7 @@
 /** Bad input parameters to function. */
 #define MBEDTLS_ERR_GCM_BAD_INPUT                         -0x0014
 /** An output buffer is too small. */
-#define MBEDTLS_ERR_GCM_BUFFER_TOO_SMALL                  -0x0018
+#define MBEDTLS_ERR_GCM_BUFFER_TOO_SMALL                  -0x0016
 
 #ifdef __cplusplus
 extern "C" {