diff --git a/debian/changelog b/debian/changelog
index fc885bbb..322b3c73 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,10 @@
+llvm-toolchain-18 (1:18.1.8-12) UNRELEASED; urgency=medium
+
+  * Ensure that at least 1 CPU is used for build
+    (Closes: #1082359)
+
+ -- Sylvestre Ledru <sylvestre@debian.org>  Fri, 20 Sep 2024 13:22:50 +0200
+
 llvm-toolchain-18 (1:18.1.8-11) unstable; urgency=medium
 
   * Drop ocaml on armhf, ocamlopt disappeared making build ftbfs
diff --git a/debian/rules b/debian/rules
index f66bcc7d..934186ff 100755
--- a/debian/rules
+++ b/debian/rules
@@ -60,7 +60,7 @@ else
 endif
 NJOBS := $(shell mt=`awk '/^(MemAvail|SwapFree)/ { mt += $$2 } END {print mt}' /proc/meminfo`; \
 		awk -vn=$(NCPUS) -vmt=$$mt -vm=$(MEM_PER_CPU) \
-		  'END { mt/=1024; n2 = int(mt/m); print n==1 ? 1 : n2<n+1 ? n2 : n+1}' < /dev/null)
+		  'END { mt/=1024; n2 = int(mt/m); print n==1 || n2<=1 ? 1 : n2<=n ? n2 : n }' < /dev/null)
 
 DH_VERSION := $(shell dpkg -s debhelper | grep '^Version' | awk '{print $$2}')