diff --git a/pipewire-jack/src/pw-jack.in b/pipewire-jack/src/pw-jack.in
index 555d4d886..2ff590c94 100755
--- a/pipewire-jack/src/pw-jack.in
+++ b/pipewire-jack/src/pw-jack.in
@@ -53,7 +53,7 @@ done
 
 shift $(( $OPTIND - 1 ))
 
-LD_LIBRARY_PATH=@LIBJACK_PATH@:$LD_LIBRARY_PATH
+LD_LIBRARY_PATH='@LIBJACK_PATH@'"${LD_LIBRARY_PATH+":$LD_LIBRARY_PATH"}"
 export LD_LIBRARY_PATH
 
 exec "$@"
diff --git a/pipewire-pulseaudio/src/pw-pulse.in b/pipewire-pulseaudio/src/pw-pulse.in
index 72ff62f55..a8c470bba 100755
--- a/pipewire-pulseaudio/src/pw-pulse.in
+++ b/pipewire-pulseaudio/src/pw-pulse.in
@@ -53,7 +53,7 @@ done
 
 shift $(( $OPTIND - 1 ))
 
-LD_LIBRARY_PATH=@LIBPULSE_PATH@:$LD_LIBRARY_PATH
+LD_LIBRARY_PATH='@LIBPULSE_PATH@'"${LD_LIBRARY_PATH+":$LD_LIBRARY_PATH"}"
 export LD_LIBRARY_PATH
 
 exec "$@"
diff --git a/pw-uninstalled.sh b/pw-uninstalled.sh
index c1af6bbcd..0ed106caf 100755
--- a/pw-uninstalled.sh
+++ b/pw-uninstalled.sh
@@ -35,8 +35,8 @@ export PIPEWIRE_CONFIG_FILE="${BUILDDIR}/src/daemon/pipewire.conf"
 export SPA_PLUGIN_DIR="${BUILDDIR}/spa/plugins"
 export PIPEWIRE_MODULE_DIR="${BUILDDIR}/src/modules"
 export PATH="${BUILDDIR}/src/daemon:${BUILDDIR}/src/tools:${BUILDDIR}/src/examples:${PATH}"
-export LD_LIBRARY_PATH="${BUILDDIR}/pipewire-pulseaudio/src/:${BUILDDIR}/src/pipewire/:${BUILDDIR}/pipewire-jack/src/:${LD_LIBRARY_PATH}"
-export GST_PLUGIN_PATH="${BUILDDIR}/src/gst/:${GST_PLUGIN_PATH}"
+export LD_LIBRARY_PATH="${BUILDDIR}/pipewire-pulseaudio/src/:${BUILDDIR}/src/pipewire/:${BUILDDIR}/pipewire-jack/src/${LD_LIBRARY_PATH+":$LD_LIBRARY_PATH"}"
+export GST_PLUGIN_PATH="${BUILDDIR}/src/gst/${GST_PLUGIN_PATH+":${GST_PLUGIN_PATH}"}"
 
 # FIXME: find a nice, shell-neutral way to specify a prompt
 ${SHELL}