diff --git a/base16384.h b/base16384.h
index 288380e..e0631a8 100644
--- a/base16384.h
+++ b/base16384.h
@@ -78,7 +78,7 @@ typedef ssize_t(*base16384_reader_t)(const void *client_data, void *buffer, size
 typedef ssize_t(*base16384_writer_t)(const void *client_data, const void *buffer, size_t count);
 
 struct base16384_stream_t {
-	union {
+	const union {
 		base16384_reader_t reader;
 		base16384_writer_t writer;
 	} f;
diff --git a/test/file_test.h b/test/file_test.h
index 06f6745..b44fe8b 100644
--- a/test/file_test.h
+++ b/test/file_test.h
@@ -100,7 +100,8 @@ static ssize_t base16384_test_file_reader(const void *client_data, void *buffer,
     int fd = (int)((uintptr_t)client_data);
     ssize_t ret = read(fd, buffer, count);
     if(ret < 0) return ret;
-    for(ssize_t i = 0; i < ret; i++) {
+    ssize_t i;
+    for(i = 0; i < ret; i++) {
         ((uint8_t*)(buffer))[i] = ~((uint8_t*)(buffer))[i];
     }
     return ret;
@@ -114,7 +115,8 @@ static ssize_t base16384_test_file_writer(const void *client_data, const void *b
     }
     uint8_t* wbuf = (uint8_t*)malloc(count);
     if(!wbuf) return -200;
-    for(ssize_t i = 0; i < count; i++) {
+    ssize_t i;
+    for(i = 0; i < count; i++) {
         wbuf[i] = ~((uint8_t*)(buffer))[i];
     }
     ssize_t ret = write(fd, buffer, count);