diff --git a/libcortex_a9/src/lib.rs b/libcortex_a9/src/lib.rs
index e443bad..00814a9 100644
--- a/libcortex_a9/src/lib.rs
+++ b/libcortex_a9/src/lib.rs
@@ -56,8 +56,8 @@ macro_rules! interrupt_handler {
             asm!(
                 // setup SP, depending on CPU 0 or 1
                 // and preserve registers
-                "SUB lr, lr, #4",
-                "STMFD sp!, {{r0-r12, lr}}",
+                "sub lr, lr, #4",
+                "stmfd sp!, {{r0-r12, lr}}",
                 "mrc p15, #0, r0, c0, c0, #5",
                 concat!("movw r1, :lower16:", stringify!($stack0)),
                 concat!("movt r1, :upper16:", stringify!($stack0)),
@@ -70,7 +70,7 @@ macro_rules! interrupt_handler {
                 concat!("bl ", stringify!($name2)),
                 "pop {{r0, r1}}",
                 "mov sp, r0",
-                "LDMFD sp!, {{r0-r12, pc}}^",                           // caret ^ : copy SPSR to the CPSR  
+                "ldmfd sp!, {{r0-r12, pc}}^",                           // caret ^ : copy SPSR to the CPSR  
                 options(noreturn)
             );
         }