diff --git a/core/compat/getarch.c b/core/compat/getarch.c
index fc9be09f..5d29ff77 100644
--- a/core/compat/getarch.c
+++ b/core/compat/getarch.c
@@ -34,7 +34,7 @@
 
 #endif
 
-main()
+int main()
 {
   printf(ARCH "\n");
 }
diff --git a/core/compat/getos.c b/core/compat/getos.c
index 2f551668..1185dafb 100644
--- a/core/compat/getos.c
+++ b/core/compat/getos.c
@@ -32,7 +32,7 @@
 # warning "Could not detect the OS"
 #endif
 
-main()
+int main()
 {
   printf(OS "\n");
 }