Index: uspace/lib/c/include/stdio.h
===================================================================
--- uspace/lib/c/include/stdio.h	(revision 1d0d06ab3697bcf26d50afc7b5b9c7c80b9e0abc)
+++ uspace/lib/c/include/stdio.h	(revision 97e660ea1cb30e6bf61844acec398d6a9008dac8)
@@ -41,4 +41,15 @@
 #include <adt/list.h>
 
+#ifndef NVERIFY_PRINTF
+
+#define PRINTF_ATTRIBUTE(start, end) \
+	__attribute__((format(gnu_printf, start, end)))
+
+#else /* NVERIFY_PRINTF */
+
+#define PRINTF_ATTRIBUTE(start, end)
+
+#endif /* NVERIFY_PRINTF */
+
 #define EOF  (-1)
 
@@ -149,12 +160,16 @@
 
 /* Formatted string output functions */
-extern int fprintf(FILE *, const char*, ...);
+extern int fprintf(FILE *, const char*, ...)
+    PRINTF_ATTRIBUTE(2, 3);
 extern int vfprintf(FILE *, const char *, va_list);
 
-extern int printf(const char *, ...);
+extern int printf(const char *, ...)
+    PRINTF_ATTRIBUTE(1, 2);
 extern int vprintf(const char *, va_list);
 
-extern int snprintf(char *, size_t , const char *, ...);
-extern int asprintf(char **, const char *, ...);
+extern int snprintf(char *, size_t , const char *, ...)
+    PRINTF_ATTRIBUTE(3, 4);
+extern int asprintf(char **, const char *, ...)
+    PRINTF_ATTRIBUTE(2, 3);
 extern int vsnprintf(char *, size_t, const char *, va_list);