diff --git a/src/examples/hello-wasm-unknown/main.go b/src/examples/hello-wasm-unknown/main.go
index 557f4a3c36..ff2ec88f18 100644
--- a/src/examples/hello-wasm-unknown/main.go
+++ b/src/examples/hello-wasm-unknown/main.go
@@ -3,6 +3,10 @@
 // tinygo build -size short -o hello-unknown.wasm -target wasm-unknown -gc=leaking -no-debug ./src/examples/hello-wasm-unknown/
 package main
 
+// Smoke test: make sure the fmt package can be imported (even if it isn't
+// really useful for wasm-unknown).
+import _ "os"
+
 var x int32
 
 //go:wasmimport hosted echo_i32
diff --git a/src/os/dir_other.go b/src/os/dir_other.go
index 9a1b394213..60cd9f8e6a 100644
--- a/src/os/dir_other.go
+++ b/src/os/dir_other.go
@@ -1,4 +1,4 @@
-//go:build baremetal || js || windows
+//go:build baremetal || js || windows || wasm_unknown
 
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
diff --git a/src/os/dir_unix.go b/src/os/dir_unix.go
index a531e0a639..227dc9188d 100644
--- a/src/os/dir_unix.go
+++ b/src/os/dir_unix.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build linux && !baremetal && !wasip1
+//go:build linux && !baremetal && !wasip1 && !wasm_unknown
 
 package os
 
diff --git a/src/os/dirent_linux.go b/src/os/dirent_linux.go
index 90f7086db8..790c26890f 100644
--- a/src/os/dirent_linux.go
+++ b/src/os/dirent_linux.go
@@ -1,4 +1,4 @@
-//go:build !baremetal && !js && !wasip1
+//go:build !baremetal && !js && !wasip1 && !wasm_unknown
 
 // Copyright 2020 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
diff --git a/src/os/file_anyos.go b/src/os/file_anyos.go
index 0436d1222e..1483f11c2a 100644
--- a/src/os/file_anyos.go
+++ b/src/os/file_anyos.go
@@ -1,4 +1,4 @@
-//go:build !baremetal && !js
+//go:build !baremetal && !js && !wasm_unknown
 
 // Portions copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
diff --git a/src/os/file_other.go b/src/os/file_other.go
index e7fabddcaf..82552c1a8c 100644
--- a/src/os/file_other.go
+++ b/src/os/file_other.go
@@ -1,4 +1,4 @@
-//go:build baremetal || (wasm && !wasip1)
+//go:build baremetal || (tinygo.wasm && !wasip1)
 
 package os
 
diff --git a/src/os/file_unix.go b/src/os/file_unix.go
index 25f0266a67..25c2161e3e 100644
--- a/src/os/file_unix.go
+++ b/src/os/file_unix.go
@@ -1,4 +1,4 @@
-//go:build darwin || (linux && !baremetal) || wasip1
+//go:build darwin || (linux && !baremetal && !wasm_unknown) || wasip1
 
 // target wasi sets GOOS=linux and thus the +linux build tag,
 // even though it doesn't show up in "tinygo info target -wasi"
diff --git a/src/os/removeall_noat.go b/src/os/removeall_noat.go
index 8b03756e31..d49162768c 100644
--- a/src/os/removeall_noat.go
+++ b/src/os/removeall_noat.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !baremetal && !js && !wasip1
+//go:build !baremetal && !js && !wasip1 && !wasm_unknown
 
 package os
 
diff --git a/src/os/removeall_other.go b/src/os/removeall_other.go
index ec055a9875..75346bc838 100644
--- a/src/os/removeall_other.go
+++ b/src/os/removeall_other.go
@@ -1,4 +1,4 @@
-//go:build baremetal || js || wasi || wasip1
+//go:build baremetal || js || wasi || wasip1 || wasm_unknown
 
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
diff --git a/src/os/stat_linuxlike.go b/src/os/stat_linuxlike.go
index f2ff8a5f61..59ee649707 100644
--- a/src/os/stat_linuxlike.go
+++ b/src/os/stat_linuxlike.go
@@ -1,4 +1,4 @@
-//go:build (linux && !baremetal) || wasip1
+//go:build (linux && !baremetal && !wasm_unknown) || wasip1
 
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
diff --git a/src/os/stat_other.go b/src/os/stat_other.go
index 7340fbb574..d3e0af6ed5 100644
--- a/src/os/stat_other.go
+++ b/src/os/stat_other.go
@@ -1,4 +1,4 @@
-//go:build baremetal || (wasm && !wasip1)
+//go:build baremetal || (tinygo.wasm && !wasip1)
 
 // Copyright 2016 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
diff --git a/src/os/stat_unix.go b/src/os/stat_unix.go
index 54b2bb4857..a3aa491f36 100644
--- a/src/os/stat_unix.go
+++ b/src/os/stat_unix.go
@@ -1,4 +1,4 @@
-//go:build darwin || (linux && !baremetal) || wasip1
+//go:build darwin || (linux && !baremetal && !wasm_unknown) || wasip1
 
 // Copyright 2016 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
diff --git a/src/os/types_anyos.go b/src/os/types_anyos.go
index cb3a0b9491..939c00967c 100644
--- a/src/os/types_anyos.go
+++ b/src/os/types_anyos.go
@@ -1,4 +1,4 @@
-//go:build !baremetal && !js
+//go:build !baremetal && !js && !wasm_unknown
 
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
diff --git a/src/os/types_unix.go b/src/os/types_unix.go
index 943fc00f52..3a552dfd94 100644
--- a/src/os/types_unix.go
+++ b/src/os/types_unix.go
@@ -1,4 +1,4 @@
-//go:build darwin || (linux && !baremetal) || wasip1
+//go:build darwin || (linux && !baremetal && !wasm_unknown) || wasip1
 
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
diff --git a/src/runtime/nonhosted.go b/src/runtime/nonhosted.go
index 6b47ba8b0c..ca5ab4c3c8 100644
--- a/src/runtime/nonhosted.go
+++ b/src/runtime/nonhosted.go
@@ -1,4 +1,4 @@
-//go:build baremetal || js
+//go:build baremetal || js || wasm_unknown
 
 package runtime
 
diff --git a/src/runtime/runtime_wasm_unknown.go b/src/runtime/runtime_wasm_unknown.go
index 111bddf085..d307a4f87e 100644
--- a/src/runtime/runtime_wasm_unknown.go
+++ b/src/runtime/runtime_wasm_unknown.go
@@ -23,8 +23,6 @@ func init() {
 	__wasm_call_ctors()
 }
 
-var args []string
-
 func ticksToNanoseconds(ticks timeUnit) int64 {
 	return int64(ticks)
 }