diff --git a/src/syscalls/fopen.c b/src/syscalls/fopen.c
index d6416533..e8ca6dd9 100644
--- a/src/syscalls/fopen.c
+++ b/src/syscalls/fopen.c
@@ -15,7 +15,7 @@
 static uint8_t already_writing = 0;
 
 #undef fopen
-FILE *FTLfopen(const char *pathname, const char *mode, const char *file, const char *func, const int line)
+FILE * __attribute__ ((__malloc__)) FTLfopen(const char *pathname, const char *mode, const char *file, const char *func, const int line)
 {
 	FILE *file_ptr = 0;
 	do
diff --git a/src/syscalls/syscalls.h b/src/syscalls/syscalls.h
index 1b2787cd..dfe1a178 100644
--- a/src/syscalls/syscalls.h
+++ b/src/syscalls/syscalls.h
@@ -45,7 +45,7 @@ ssize_t FTLsendto(int sockfd, void *buf, size_t len, int flags, const struct soc
 int FTLpthread_mutex_lock(pthread_mutex_t *__mutex, const char *file, const char *func, const int line);
 
 // Interrupt-safe file routines
-FILE *FTLfopen(const char *pathname, const char *mode, const char *file, const char *func, const int line);
+FILE *FTLfopen(const char *pathname, const char *mode, const char *file, const char *func, const int line) __attribute__ ((__malloc__));
 
 // Syscall helpers
 void syscalls_report_error(const char *error, FILE *stream, const int _errno, const char *format, const char *func, const char *file, const int line);