diff --git a/include/libbb.h b/include/libbb.h
index 1f39c95..8d3df61 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -869,6 +869,7 @@
 int sanitize_env_if_suid(void) FAST_FUNC;
 
 
+char* single_argv(char **argv) FAST_FUNC;
 extern const char *const bb_argv_dash[]; /* "-", NULL */
 extern const char *opt_complementary;
 #if ENABLE_LONG_OPTS || ENABLE_FEATURE_GETOPT_LONG