diff --git a/core/runtime/os_specific.odin b/core/runtime/os_specific.odin
index e09acb51c..ab2d78007 100644
--- a/core/runtime/os_specific.odin
+++ b/core/runtime/os_specific.odin
@@ -1,45 +1,24 @@
+//+build !freestanding
 package runtime
 
-when ODIN_OS == "freestanding" {
-	_OS_Errno  :: distinct int;
-	_OS_Handle :: distinct uintptr;
+import "core:os"
 
-	os_stdout :: proc "contextless" () -> _OS_Handle {
-		return 1;
-	}
-	os_stderr :: proc "contextless" () -> _OS_Handle {
-		return 2;
-	}
+_OS_Errno  :: distinct int;
+_OS_Handle :: os.Handle;
 
-	// TODO(bill): reimplement `os.write`
-	os_write :: proc(fd: _OS_Handle, data: []byte) -> (int, _OS_Errno) {
-		return 0, -1;
-	}
-
-	current_thread_id :: proc "contextless" () -> int {
-		return 0;
-	}
-
-} else {
-	import "core:os"
-
-	_OS_Errno  :: distinct int;
-	_OS_Handle :: os.Handle;
-
-	os_stdout :: proc "contextless" () -> _OS_Handle {
-		return os.stdout;
-	}
-	os_stderr :: proc "contextless" () -> _OS_Handle {
-		return os.stderr;
-	}
-
-	// TODO(bill): reimplement `os.write`
-	os_write :: proc(fd: _OS_Handle, data: []byte) -> (int, _OS_Errno) {
-		n, err := os.write(fd, data);
-		return int(n), _OS_Errno(err);
-	}
-
-	current_thread_id :: proc "contextless" () -> int {
-		return os.current_thread_id();
-	}
+os_stdout :: proc "contextless" () -> _OS_Handle {
+	return os.stdout;
+}
+os_stderr :: proc "contextless" () -> _OS_Handle {
+	return os.stderr;
+}
+
+// TODO(bill): reimplement `os.write`
+os_write :: proc(fd: _OS_Handle, data: []byte) -> (int, _OS_Errno) {
+	n, err := os.write(fd, data);
+	return int(n), _OS_Errno(err);
+}
+
+current_thread_id :: proc "contextless" () -> int {
+	return os.current_thread_id();
 }
diff --git a/core/runtime/os_specific_freestanding.odin b/core/runtime/os_specific_freestanding.odin
new file mode 100644
index 000000000..3906e3ed7
--- /dev/null
+++ b/core/runtime/os_specific_freestanding.odin
@@ -0,0 +1,21 @@
+//+build freestanding
+package runtime
+
+_OS_Errno  :: distinct int;
+_OS_Handle :: distinct uintptr;
+
+os_stdout :: proc "contextless" () -> _OS_Handle {
+	return 1;
+}
+os_stderr :: proc "contextless" () -> _OS_Handle {
+	return 2;
+}
+
+// TODO(bill): reimplement `os.write`
+os_write :: proc(fd: _OS_Handle, data: []byte) -> (int, _OS_Errno) {
+	return 0, -1;
+}
+
+current_thread_id :: proc "contextless" () -> int {
+	return 0;
+}
diff --git a/src/parser.cpp b/src/parser.cpp
index 868291177..2ddad3b58 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -4821,16 +4821,16 @@ bool parse_build_tag(Token token_for_pos, String s) {
 				TargetArchKind arch = get_target_arch_from_string(p);
 				if (os != TargetOs_Invalid) {
 					GB_ASSERT(arch == TargetArch_Invalid);
-					if (is_notted && os == build_context.metrics.os) {
-						this_kind_correct = false;
-					} else if (os != build_context.metrics.os) {
-						this_kind_correct = false;
+					if (is_notted) {
+						this_kind_correct = this_kind_correct && (os != build_context.metrics.os);
+					} else {
+						this_kind_correct = this_kind_correct && (os == build_context.metrics.os);
 					}
 				} else if (arch != TargetArch_Invalid) {
-					if (is_notted && arch == build_context.metrics.arch) {
-						this_kind_correct = false;
-					} else if (arch != build_context.metrics.arch) {
-						this_kind_correct = false;
+					if (is_notted) {
+						this_kind_correct = this_kind_correct && (arch != build_context.metrics.arch);
+					} else {
+						this_kind_correct = this_kind_correct && (arch == build_context.metrics.arch);
 					}
 				}
 				if (os == TargetOs_Invalid && arch == TargetArch_Invalid) {