diff --git a/signal_handler.h b/signal_handler.h
index 939a582..756273f 100644
--- a/signal_handler.h
+++ b/signal_handler.h
@@ -9,6 +9,6 @@
 #ifndef SIGNAL_HANDLER_H
 #define SIGNAL_HANDLER_H
 
-int install_sigsys_handler();
+int install_sigsys_handler(void);
 
 #endif /* SIGNAL_HANDLER_H */
diff --git a/util.h b/util.h
index 9c74cdb..14e79f5 100644
--- a/util.h
+++ b/util.h
@@ -42,7 +42,7 @@
 extern const char *log_syscalls[];
 extern const size_t log_syscalls_len;
 
-static inline int is_android()
+static inline int is_android(void)
 {
 #if defined(__ANDROID__)
 	return 1;
@@ -53,7 +53,7 @@
 
 void __asan_init(void) __attribute__((weak));
 
-static inline int running_with_asan()
+static inline int running_with_asan(void)
 {
 	return &__asan_init != 0;
 }