diff --git a/src/select/poll.c b/src/select/poll.c
index f1e73e8..b2f8b00 100644
--- a/src/select/poll.c
+++ b/src/select/poll.c
@@ -6,3 +6,5 @@ int poll(struct pollfd *fds, nfds_t n, int timeout)
 {
 	return syscall_cp(SYS_poll, fds, n, timeout);
 }
+
+weak_alias(poll, __poll);
diff --git a/src/stdio/fscanf.c b/src/stdio/fscanf.c
index 51fc9b3..155f8ac 100644
--- a/src/stdio/fscanf.c
+++ b/src/stdio/fscanf.c
@@ -1,5 +1,6 @@
 #include <stdio.h>
 #include <stdarg.h>
+#include "libc.h"
 
 int fscanf(FILE *f, const char *fmt, ...)
 {
@@ -10,3 +11,5 @@ int fscanf(FILE *f, const char *fmt, ...)
 	va_end(ap);
 	return ret;
 }
+
+weak_alias(fscanf, __isoc99_fscanf);
diff --git a/src/stdio/sscanf.c b/src/stdio/sscanf.c
index a1cea69..8c16343 100644
--- a/src/stdio/sscanf.c
+++ b/src/stdio/sscanf.c
@@ -1,5 +1,6 @@
 #include <stdio.h>
 #include <stdarg.h>
+#include "libc.h"
 
 int sscanf(const char *s, const char *fmt, ...)
 {
@@ -10,3 +11,5 @@ int sscanf(const char *s, const char *fmt, ...)
 	va_end(ap);
 	return ret;
 }
+
+weak_alias(sscanf, __isoc99_sscanf);
diff --git a/src/string/strndup.c b/src/string/strndup.c
index 617d27b..b162d8b 100644
--- a/src/string/strndup.c
+++ b/src/string/strndup.c
@@ -1,7 +1,8 @@
 #include <stdlib.h>
 #include <string.h>
+#include "libc.h"
 
-char *strndup(const char *s, size_t n)
+char *__strndup(const char *s, size_t n)
 {
 	size_t l = strnlen(s, n);
 	char *d = malloc(l+1);
@@ -10,3 +11,5 @@ char *strndup(const char *s, size_t n)
 	d[l] = 0;
 	return d;
 }
+
+weak_alias(__strndup, strndup);