diff --git a/debian/changelog b/debian/changelog
index 43f3d10ca943..1ca82810e741 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -52,6 +52,7 @@ linux (5.2.5-1) UNRELEASED; urgency=medium
   * [ppc64*] crypto: Enable CRYPTO_DEV_NX, and CRYPTO_DEV_NX_ENCRYPT,
     CRYPTO_DEV_NX_COMPRESS, CRYPTO_DEV_NX_COMPRESS_PSERIES,
     CRYPTO_DEV_NX_COMPRESS_POWERNV as modules (Closes: #931374)
+  * [ppc64*] Disable PPC_TRANSACTIONAL_MEM (Closes: #866122)
 
   [ Vagrant Cascadian ]
   * [arm64] Enable modules to support audio on pinebook: SND_SUN4I_I2S,
diff --git a/debian/config/kernelarch-powerpc/config-arch-64 b/debian/config/kernelarch-powerpc/config-arch-64
index 2610692ad20c..d023e5d73bd9 100644
--- a/debian/config/kernelarch-powerpc/config-arch-64
+++ b/debian/config/kernelarch-powerpc/config-arch-64
@@ -1,7 +1,8 @@
 ##
 ## file: arch/powerpc/Kconfig
 ##
-CONFIG_PPC_TRANSACTIONAL_MEM=y
+#. This feature is broken; see #866122
+# CONFIG_PPC_TRANSACTIONAL_MEM is not set
 CONFIG_CRASH_DUMP=y
 CONFIG_IRQ_ALL_CPUS=y
 CONFIG_NUMA=y