diff --git a/healthcheck/diskcheck.go b/healthcheck/diskcheck.go
index 7f30b154..087fc7a7 100644
--- a/healthcheck/diskcheck.go
+++ b/healthcheck/diskcheck.go
@@ -1,4 +1,4 @@
-// +build !windows,!solaris,!netbsd,!openbsd
+// +build !windows,!solaris,!netbsd,!openbsd,!js
 
 package healthcheck
 
diff --git a/healthcheck/diskcheck_js.go b/healthcheck/diskcheck_js.go
new file mode 100644
index 00000000..4a2f4f57
--- /dev/null
+++ b/healthcheck/diskcheck_js.go
@@ -0,0 +1,13 @@
+package healthcheck
+
+// AvailableDiskSpaceRatio returns ratio of available disk space to total
+// capacity.
+func AvailableDiskSpaceRatio(path string) (float64, error) {
+	return 0, fmt.Errorf("disk space check not supported in WebAssembly")
+}
+
+// AvailableDiskSpace returns the available disk space in bytes of the given
+// file system.
+func AvailableDiskSpace(path string) (uint64, error) {
+	return 0, fmt.Errorf("disk space check not supported in WebAssembly")
+}