diff --git a/mos-platform/common/c/stdio-minimal.c b/mos-platform/common/c/stdio-minimal.c
index 5a2fdc67..b32a8f6d 100644
--- a/mos-platform/common/c/stdio-minimal.c
+++ b/mos-platform/common/c/stdio-minimal.c
@@ -5,9 +5,10 @@
 #include <stdint.h>
 #include <string.h>
 
-__attribute__((weak)) FILE *stdin;
-__attribute__((weak)) FILE *stdout;
-__attribute__((weak)) FILE *stderr;
+// These need to be non-null, but their contents otherwise doesn't matter.
+__attribute__((weak)) FILE *stdin = (FILE *)1;
+__attribute__((weak)) FILE *stdout = (FILE *)1;
+__attribute__((weak)) FILE *stderr = (FILE *)1;
 
 // Character input/output functions