diff --git a/src/device/arm/cortexm.s b/src/device/arm/cortexm.S
similarity index 100%
rename from src/device/arm/cortexm.s
rename to src/device/arm/cortexm.S
diff --git a/src/runtime/runtime_nintendoswitch.s b/src/runtime/runtime_nintendoswitch.S
similarity index 100%
rename from src/runtime/runtime_nintendoswitch.s
rename to src/runtime/runtime_nintendoswitch.S
diff --git a/targets/cortex-m.json b/targets/cortex-m.json
index 8a1e8025..7b1f7511 100644
--- a/targets/cortex-m.json
+++ b/targets/cortex-m.json
@@ -22,7 +22,7 @@
 		"--gc-sections"
 	],
 	"extra-files": [
-		"src/device/arm/cortexm.s",
+		"src/device/arm/cortexm.S",
 		"src/internal/task/task_stack_cortexm.S",
 		"src/runtime/asm_arm.S"
 	],
diff --git a/targets/nintendoswitch.json b/targets/nintendoswitch.json
index a04133ba..f85ee718 100644
--- a/targets/nintendoswitch.json
+++ b/targets/nintendoswitch.json
@@ -30,6 +30,6 @@
     "targets/nintendoswitch.s",
     "src/internal/task/task_stack_arm64.S",
     "src/runtime/asm_arm64.S",
-    "src/runtime/runtime_nintendoswitch.s"
+    "src/runtime/runtime_nintendoswitch.S"
   ]
 }