diff --git a/contrib/make_libsecp256k1.sh b/contrib/make_libsecp256k1.sh
index f1c1f1efa..275221049 100755
--- a/contrib/make_libsecp256k1.sh
+++ b/contrib/make_libsecp256k1.sh
@@ -20,7 +20,7 @@ set -e
 
 . $(dirname "$0")/build_tools_util.sh || (echo "Could not source build_tools_util.sh" && exit 1)
 
-here=$(dirname $(realpath "$0" 2> /dev/null || grealpath "$0"))
+here="$(dirname "$(realpath "$0" 2> /dev/null || grealpath "$0")")"
 CONTRIB="$here"
 PROJECT_ROOT="$CONTRIB/.."
 
@@ -28,7 +28,7 @@ pkgname="secp256k1"
 info "Building $pkgname..."
 
 (
-    cd $CONTRIB
+    cd "$CONTRIB"
     if [ ! -d secp256k1 ]; then
         git clone https://github.com/bitcoin-core/secp256k1.git
     fi
diff --git a/contrib/make_libusb.sh b/contrib/make_libusb.sh
index 6f4bcf4e7..dfa9671f4 100755
--- a/contrib/make_libusb.sh
+++ b/contrib/make_libusb.sh
@@ -7,7 +7,7 @@ set -e
 
 . $(dirname "$0")/build_tools_util.sh || (echo "Could not source build_tools_util.sh" && exit 1)
 
-here=$(dirname $(realpath "$0" 2> /dev/null || grealpath "$0"))
+here="$(dirname "$(realpath "$0" 2> /dev/null || grealpath "$0")")"
 CONTRIB="$here"
 PROJECT_ROOT="$CONTRIB/.."
 
@@ -15,7 +15,7 @@ pkgname="libusb"
 info "Building $pkgname..."
 
 (
-    cd $CONTRIB
+    cd "$CONTRIB"
     if [ ! -d libusb ]; then
         git clone https://github.com/libusb/libusb.git
     fi
diff --git a/contrib/make_zbar.sh b/contrib/make_zbar.sh
index de60c68ab..7546def65 100755
--- a/contrib/make_zbar.sh
+++ b/contrib/make_zbar.sh
@@ -16,7 +16,7 @@ set -e
 
 . $(dirname "$0")/build_tools_util.sh || (echo "Could not source build_tools_util.sh" && exit 1)
 
-here=$(dirname $(realpath "$0" 2> /dev/null || grealpath "$0"))
+here="$(dirname "$(realpath "$0" 2> /dev/null || grealpath "$0")")"
 CONTRIB="$here"
 PROJECT_ROOT="$CONTRIB/.."
 
@@ -24,7 +24,7 @@ pkgname="zbar"
 info "Building $pkgname..."
 
 (
-    cd $CONTRIB
+    cd "$CONTRIB"
     if [ ! -d zbar ]; then
         git clone https://github.com/mchehab/zbar.git
     fi