diff --git a/vlib/runtime/free_memory_impl_openbsd.c.v b/vlib/runtime/free_memory_impl_openbsd.c.v
new file mode 100644
index 0000000000..30b9b7c201
--- /dev/null
+++ b/vlib/runtime/free_memory_impl_openbsd.c.v
@@ -0,0 +1,15 @@
+module runtime
+
+fn free_memory_impl() usize {
+	$if cross ? {
+		return 1
+	}
+	$if !cross ? {
+		$if openbsd {
+			page_size := usize(C.sysconf(C._SC_PAGESIZE))
+			av_phys_pages := usize(C.sysconf(C._SC_AVPHYS_PAGES))
+			return page_size * av_phys_pages
+		}
+	}
+	return 1
+}