diff --git a/library/hmac_drbg.c b/library/hmac_drbg.c
index bf5f9b5..2961750 100644
--- a/library/hmac_drbg.c
+++ b/library/hmac_drbg.c
@@ -355,10 +355,10 @@
         goto exit;
 
     if( fwrite( buf, 1, sizeof( buf ), f ) != sizeof( buf ) )
-    {
+    { // LCOV_EXCL_START
         ret = MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR;
         goto exit;
-    }
+    } // LCOV_EXCL_STOP
 
     ret = 0;
 
@@ -387,10 +387,10 @@
     }
 
     if( fread( buf, 1, n, f ) != n )
-    {
+    { // LCOV_EXCL_START
         fclose( f );
         return( MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR );
-    }
+    } // LCOV_EXCL_STOP
 
     fclose( f );