diff --git a/changelog/subpackage_upgrade.dd b/changelog/subpackage_upgrade.dd
new file mode 100644
index 0000000..c9a28ce
--- /dev/null
+++ b/changelog/subpackage_upgrade.dd
@@ -0,0 +1,5 @@
+Upgrading all sub packages at once
+
+A new "-s" switch allows to "dub upgrade" all sub packages together with the
+base package. This aims to provide a better workflow for fully reproducible
+builds and tests.
diff --git a/source/dub/commandline.d b/source/dub/commandline.d
index 246f8e5..946a6e4 100644
--- a/source/dub/commandline.d
+++ b/source/dub/commandline.d
@@ -1758,6 +1758,7 @@
 class UpgradeCommand : Command {
 	private {
 		bool m_prerelease = false;
+		bool m_includeSubPackages = false;
 		bool m_forceRemove = false;
 		bool m_missingOnly = false;
 		bool m_verify = false;
@@ -1783,6 +1784,9 @@
 		args.getopt("prerelease", &m_prerelease, [
 			"Uses the latest pre-release version, even if release versions are available"
 		]);
+		args.getopt("s|sub-packages", &m_includeSubPackages, [
+			"Also upgrades dependencies of all directory based sub packages"
+		]);
 		args.getopt("verify", &m_verify, [
 			"Updates the project and performs a build. If successful, rewrites the selected versions file <to be implemented>."
 		]);
@@ -1809,6 +1813,41 @@
 		if (m_prerelease) options |= UpgradeOptions.preRelease;
 		if (m_dryRun) options |= UpgradeOptions.dryRun;
 		dub.upgrade(options, free_args);
+
+		auto spacks = dub.project.rootPackage
+			.subPackages
+			.filter!(sp => sp.path.length);
+
+		if (m_includeSubPackages) {
+			bool any_error = false;
+
+			// Go through each path based sub package, load it as a new instance
+			// and perform an upgrade as if the upgrade had been run from within
+			// the sub package folder. Note that we have to use separate Dub
+			// instances, because the upgrade always works on the root package
+			// of a project, which in this case are the individual sub packages.
+			foreach (sp; spacks) {
+				try {
+					auto fullpath = (dub.projectPath ~ sp.path).toNativeString();
+					logInfo("Upgrading sub package in %s", fullpath);
+					auto sdub = new Dub(fullpath, dub.packageSuppliers, SkipPackageSuppliers.all);
+					sdub.defaultPlacementLocation = dub.defaultPlacementLocation;
+					sdub.loadPackage();
+					sdub.upgrade(options, free_args);
+				} catch (Exception e) {
+					logError("Failed to update sub package at %s: %s",
+						sp.path, e.msg);
+					any_error = true;
+				}
+			}
+
+			if (any_error) return 1;
+		} else if (!spacks.empty) {
+			foreach (sp; spacks)
+				logInfo("Not upgrading sub package in %s", sp.path);
+			logInfo("\nNote: specify -s to also upgrade sub packages.");
+		}
+
 		return 0;
 	}
 }
diff --git a/source/dub/dub.d b/source/dub/dub.d
index 833aa65..c6bc832 100644
--- a/source/dub/dub.d
+++ b/source/dub/dub.d
@@ -343,6 +343,8 @@
 
 	@property inout(Project) project() inout { return m_project; }
 
+	@property inout(PackageSupplier)[] packageSuppliers() inout { return m_packageSuppliers; }
+
 	/** Returns the default compiler binary to use for building D code.
 
 		If set, the "defaultCompiler" field of the DUB user or system
diff --git a/test/test-upgrade-subpackages.sh b/test/test-upgrade-subpackages.sh
new file mode 100755
index 0000000..860e686
--- /dev/null
+++ b/test/test-upgrade-subpackages.sh
@@ -0,0 +1,29 @@
+#!/usr/bin/env bash
+
+. $(dirname ${BASH_SOURCE[0]})/common.sh
+
+PACK_PATH="$CURR_DIR"/path-subpackage-ref
+
+# make sure that there are no left-over selections files
+rm -f $PACK_PATH/dub.selections.json $PACK_PATH/subpack/dub.selections.json
+
+# first upgrade only the root package
+if ! ${DUB} upgrade --root $PACK_PATH; then
+    die $LINENO 'The upgrade command failed.'
+fi
+if [ ! -f $PACK_PATH/dub.selections.json ] || [ -f $PACK_PATH/subpack/dub.selections.json ]; then
+    die $LINENO 'The upgrade command did not generate the right set of dub.selections.json files.'
+fi
+
+rm -f $PACK_PATH/dub.selections.json
+
+# now upgrade with all sub packages
+if ! ${DUB} upgrade -s --root $PACK_PATH; then
+    die $LINENO 'The upgrade command failed with -s.'
+fi
+if [ ! -f $PACK_PATH/dub.selections.json ] || [ ! -f $PACK_PATH/subpack/dub.selections.json ]; then
+    die $LINENO 'The upgrade command did not generate all dub.selections.json files.'
+fi
+
+# clean up
+rm -f $PACK_PATH/dub.selections.json $PACK_PATH/subpack/dub.selections.json
diff --git a/test/timeout.sh b/test/timeout.sh
index 4e7f7db..eb8d3c4 100755
--- a/test/timeout.sh
+++ b/test/timeout.sh
@@ -31,7 +31,7 @@
 \r
 {}')
     for i in $(seq 0 $((${#res} - 1))); do
-        echo -n "${res:$i:1}"
+        echo -n "${res:$i:1}" || true
         sleep 1
     done
 } | nc -l $PORT >/dev/null &