diff --git a/doc/trivial_example.c b/doc/trivial_example.c
index 047ca0a2906a91188ea3b4976e751cdc265d04d5..abeba1c2da6d72128cbe628d05d3cb14048c7292 100644
--- a/doc/trivial_example.c
+++ b/doc/trivial_example.c
@@ -85,7 +85,7 @@ int main(int argc, char **argv)
       return EXIT_FAILURE;
    }
    inFile = argv[1];
-   fin = fopen(inFile, "r");
+   fin = fopen(inFile, "rb");
    if (fin==NULL)
    {
       fprintf(stderr, "failed to open input file: %s\n", strerror(errno));
@@ -101,7 +101,7 @@ int main(int argc, char **argv)
       return EXIT_FAILURE;
    }
    outFile = argv[2];
-   fout = fopen(outFile, "w");
+   fout = fopen(outFile, "wb");
    if (fout==NULL)
    {
       fprintf(stderr, "failed to open output file: %s\n", strerror(errno));