diff --git a/debian/rules b/debian/rules
index fe123b2..64a084a 100755
--- a/debian/rules
+++ b/debian/rules
@@ -3,7 +3,7 @@
 ## See debhelper(7) (uncomment to enable).
 ## Output every command that modifies files on the build system.
 export DH_VERBOSE = 1
-export PIKA_BUILD_ARCH = $(shell cat pika-build-arch)
+export PIKA_BUILD_ARCH = $(shell cat ../pika-build-arch)
 
 ## === the chain of command ===
 ## debuild runs a chain of dh functions in the following order: