diff --git a/contrib/devtools/build_autotools.sh b/contrib/devtools/build_autotools.sh
index 9b6f75d362..4a72be6950 100755
--- a/contrib/devtools/build_autotools.sh
+++ b/contrib/devtools/build_autotools.sh
@@ -1,26 +1,27 @@
 #!/usr/bin/env bash
 
 export LC_ALL=C
 
 set -euxo pipefail
 
 : "${TOPLEVEL:=$(git rev-parse --show-toplevel)}"
 : "${BUILD_DIR:=${TOPLEVEL}/build}"
 
 # Default to nothing
 : "${CONFIGURE_FLAGS:=}"
+: "${THREADS:=$(nproc || sysctl -n hw.ncpu)}"
 
 # Generate necessary autoconf files
 cd ${TOPLEVEL}
 ./autogen.sh
 mkdir -p "${BUILD_DIR}"
 cd ${BUILD_DIR}
 
 rm -f build.status test_bitcoin.xml
 
 read -a CONFIGURE_FLAGS <<< "$CONFIGURE_FLAGS --prefix=$(pwd)"
 
 ../configure "${CONFIGURE_FLAGS[@]}"
 
 # Run build
 make -j "${THREADS}"