diff --git a/debian/README.Debian b/debian/README.Debian
index 483143e4e1..51c475132f 100644
--- a/debian/README.Debian
+++ b/debian/README.Debian
@@ -28,6 +28,14 @@ reports on the Debian side.
 We will also examine these failures ourselves on a best-effort basis and
 attempt to fix the more serious-looking ones.
 
+Ports architectures
+-------------------
+
+The number of allowed test failures on certain Debian ports architectures
+(currently powerpc, powerpcspe, sparc64, x32) is raised greatly to help unblock
+progress for porters. Of course, as a user this means you may run into more
+bugs than usual; as mentioned above bugs reports and patches are welcome.
+
 
 Shared libraries
 ================
diff --git a/debian/changelog b/debian/changelog
index f992a12399..35e9934ae4 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,11 @@
+rustc (1.24.1+dfsg1-1) UNRELEASED; urgency=medium
+
+  * Upload to unstable.
+  * Raise allowed-test-failures to 160 on some non-release arches: powerpc,
+    powerpcspe, sparc64, x32.
+
+ -- Ximin Luo <infinity0@debian.org>  Wed, 07 Mar 2018 19:55:27 +0100
+
 rustc (1.24.1+dfsg1-1~exp2) experimental; urgency=medium
 
   * Steal some patches from Fedora to fix some test failures.
diff --git a/debian/rules b/debian/rules
index 302573bba3..176e37f51f 100755
--- a/debian/rules
+++ b/debian/rules
@@ -218,6 +218,9 @@ endif
 
 TEST_LOG = debian/rustc-tests.log
 FAILURES_ALLOWED = 5
+ifneq (,$(filter $(DEB_BUILD_ARCH), powerpc powerpcspe sparc64 x32))
+  FAILURES_ALLOWED = 160
+endif
 FAILED_TESTS = grep FAILED $(TEST_LOG) | grep -v '^test result'
 override_dh_auto_test-arch:
 # ensure that rustc_llvm is actually dynamically linked to libLLVM