diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1a4a090..2fe4ab2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -171,7 +171,9 @@ if(CMAKE_CROSSCOMPILING)
 
   # produce ASM listing
   add_custom_command(
-    TARGET firmware POST_BUILD COMMAND ${CMAKE_OBJDUMP} -CSd firmware > firmware.asm
+    TARGET firmware POST_BUILD
+    COMMAND
+      ${CMAKE_OBJDUMP} --prefix ${CMAKE_SOURCE_DIR} -CSd firmware > firmware.asm
     )
 
   # inform about the firmware's size in terminal