diff --git a/CHANGES b/CHANGES
index 164c58faef..1b23fdbe76 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+4641.	[cleanup]	Parallel builds (make -j) could fail with --with-atf /
+			--enable-developer. [RT #45373]
+
 4640.	[bug]		If query_findversion failed in query_getdb due to
 			memory failure the error status was incorrectly
 			discarded. [RT #45331]
diff --git a/unit/Makefile.in b/unit/Makefile.in
index f03cfce84f..4b169b63a4 100644
--- a/unit/Makefile.in
+++ b/unit/Makefile.in
@@ -18,6 +18,9 @@ srcdir =	@srcdir@
 VPATH =		@srcdir@
 top_srcdir =	@top_srcdir@
 
+# Attempt to disable parallel processing.
+.NOTPARALLEL:
+.NO_PARALLEL:
 SUBDIRS =	@ATFBUILD@
 TARGETS =       atf