diff --git a/freertos/__init__.py b/freertos/__init__.py
index 4f1c7762..9efda075 100644
--- a/freertos/__init__.py
+++ b/freertos/__init__.py
@@ -5,7 +5,7 @@
 class ArmFreeRTOS(Target):
     def __init__(self):
         super().__init__()
-        self.add_gnat_sources("src/s-macres__native.adb")
+        self.add_gnat_sources("src/s-macres__libc.adb")
         self.add_linker_switch("-Wl,-r", loader=None)
         self.add_linker_switch("-nostdlib", loader=None)
 
diff --git a/pikeos/__init__.py b/pikeos/__init__.py
index b0ee97f4..4bb85828 100644
--- a/pikeos/__init__.py
+++ b/pikeos/__init__.py
@@ -32,7 +32,7 @@ def has_libc(self, profile):
     def __init__(self):
         super(PikeOS, self).__init__()
         self.add_linker_script("pikeos/memory.ld")
-        self.add_gnat_sources("src/s-textio__pikeos.adb", "src/s-macres__native.adb")
+        self.add_gnat_sources("src/s-textio__pikeos.adb", "src/s-macres__libc.adb")
         self.add_gnarl_source("src/a-intnam__dummy.ads")
 
     def dump_runtime_xml(self, rts_name, rts):
diff --git a/visium/__init__.py b/visium/__init__.py
index 0b235f41..f94a8b2f 100644
--- a/visium/__init__.py
+++ b/visium/__init__.py
@@ -20,7 +20,7 @@ def has_small_memory(self):
 
     def __init__(self):
         super(Visium, self).__init__()
-        self.add_gnat_sources("src/s-macres__native.adb", "src/s-textio__stdio.adb")
+        self.add_gnat_sources("src/s-macres__libc.adb", "src/s-textio__stdio.adb")
 
     def dump_runtime_xml(self, rts_name, rts):
         return readfile("visium/mcm/runtime.xml")