diff --git a/lib/functions/general/bat-cat.sh b/lib/functions/general/bat-cat.sh
index a804d001e..df713d055 100644
--- a/lib/functions/general/bat-cat.sh
+++ b/lib/functions/general/bat-cat.sh
@@ -54,7 +54,7 @@ function run_tool_batcat() {
 
 	declare BATCAT_FN="bat-v${BATCAT_VERSION}-${BATCAT_ARCH_OS}"
 	declare BATCAT_FN_TARXZ="${BATCAT_FN}.tar.gz"
-	declare DOWN_URL="${GITHUB_SOURCE}/sharkdp/bat/releases/download/v${BATCAT_VERSION}/${BATCAT_FN_TARXZ}"
+	declare DOWN_URL="${GITHUB_SOURCE:-"https://github.com"}/sharkdp/bat/releases/download/v${BATCAT_VERSION}/${BATCAT_FN_TARXZ}"
 	declare BATCAT_BIN="${DIR_BATCAT}/${BATCAT_FN}-bin"
 	declare ACTUAL_VERSION
 
@@ -116,7 +116,7 @@ function try_download_batcat_tooling() {
 	run_host_command_logged rm -rf "${BATCAT_BIN}.tar.gz"
 
 	# EXTRA: get more syntaxes for batcat. We need Debian syntax for CONTROL files, etc.
-	run_host_command_logged wget --no-verbose --progress=dot:giga -O "${DIR_BATCAT}/sublime-debian.tar.gz.tmp" "${GITHUB_SOURCE}/barnumbirr/sublime-debian/archive/refs/heads/master.tar.gz"
+	run_host_command_logged wget --no-verbose --progress=dot:giga -O "${DIR_BATCAT}/sublime-debian.tar.gz.tmp" "${GITHUB_SOURCE:-"https://github.com"}/barnumbirr/sublime-debian/archive/refs/heads/master.tar.gz"
 	run_host_command_logged mkdir -p "${DIR_BATCAT}/temp-debian-syntax"
 	run_host_command_logged tar -xzf "${DIR_BATCAT}/sublime-debian.tar.gz.tmp" -C "${DIR_BATCAT}/temp-debian-syntax" sublime-debian-master/Syntaxes
 
diff --git a/lib/functions/general/oci-oras.sh b/lib/functions/general/oci-oras.sh
index 9d507af88..905c08ec0 100644
--- a/lib/functions/general/oci-oras.sh
+++ b/lib/functions/general/oci-oras.sh
@@ -55,7 +55,7 @@ function run_tool_oras() {
 
 	declare ORAS_FN="oras_${ORAS_VERSION}_${ORAS_OS}_${ORAS_ARCH}"
 	declare ORAS_FN_TARXZ="${ORAS_FN}.tar.gz"
-	declare DOWN_URL="${GITHUB_SOURCE}/oras-project/oras/releases/download/v${ORAS_VERSION}/${ORAS_FN_TARXZ}"
+	declare DOWN_URL="${GITHUB_SOURCE:-"https://github.com"}/oras-project/oras/releases/download/v${ORAS_VERSION}/${ORAS_FN_TARXZ}"
 	declare ORAS_BIN="${DIR_ORAS}/${ORAS_FN}"
 	declare ACTUAL_VERSION
 
diff --git a/lib/functions/general/shellcheck.sh b/lib/functions/general/shellcheck.sh
index 012b07503..30bd27f2b 100644
--- a/lib/functions/general/shellcheck.sh
+++ b/lib/functions/general/shellcheck.sh
@@ -94,7 +94,7 @@ function run_tool_shellcheck() {
 
 	declare SHELLCHECK_FN="shellcheck-v${SHELLCHECK_VERSION}.${SHELLCHECK_OS}.${SHELLCHECK_ARCH}"
 	declare SHELLCHECK_FN_TARXZ="${SHELLCHECK_FN}.tar.xz"
-	declare DOWN_URL="${GITHUB_SOURCE}/koalaman/shellcheck/releases/download/v${SHELLCHECK_VERSION}/${SHELLCHECK_FN_TARXZ}"
+	declare DOWN_URL="${GITHUB_SOURCE:-"https://github.com"}/koalaman/shellcheck/releases/download/v${SHELLCHECK_VERSION}/${SHELLCHECK_FN_TARXZ}"
 	declare SHELLCHECK_BIN="${DIR_SHELLCHECK}/${SHELLCHECK_FN}"
 	declare ACTUAL_VERSION
 
diff --git a/lib/tools/shellcheck.sh b/lib/tools/shellcheck.sh
index b8675b215..e03bb58d4 100755
--- a/lib/tools/shellcheck.sh
+++ b/lib/tools/shellcheck.sh
@@ -43,7 +43,7 @@ esac
 
 SHELLCHECK_FN="shellcheck-v${SHELLCHECK_VERSION}.${SHELLCHECK_OS}.${SHELLCHECK_ARCH}"
 SHELLCHECK_FN_TARXZ="${SHELLCHECK_FN}.tar.xz"
-DOWN_URL="${GITHUB_SOURCE:-https://github.com}/koalaman/shellcheck/releases/download/v${SHELLCHECK_VERSION}/${SHELLCHECK_FN_TARXZ}"
+DOWN_URL="${GITHUB_SOURCE:-"https://github.com"}/koalaman/shellcheck/releases/download/v${SHELLCHECK_VERSION}/${SHELLCHECK_FN_TARXZ}"
 SHELLCHECK_BIN="${DIR_SHELLCHECK}/${SHELLCHECK_FN}"
 
 if [[ ! -f "${SHELLCHECK_BIN}" ]]; then
diff --git a/lib/tools/shellfmt.sh b/lib/tools/shellfmt.sh
index 69d4ae767..ceb46b169 100755
--- a/lib/tools/shellfmt.sh
+++ b/lib/tools/shellfmt.sh
@@ -38,7 +38,7 @@ case "$MACHINE" in
 esac
 
 SHELLFMT_FN="shfmt_v${SHELLFMT_VERSION}_${SHELLFMT_OS}_${SHELLFMT_ARCH}"
-DOWN_URL="${GITHUB_SOURCE:-https://github.com}/mvdan/sh/releases/download/v${SHELLFMT_VERSION}/${SHELLFMT_FN}"
+DOWN_URL="${GITHUB_SOURCE:-"https://github.com"}/mvdan/sh/releases/download/v${SHELLFMT_VERSION}/${SHELLFMT_FN}"
 SHELLFMT_BIN="${DIR_SHELLFMT}/${SHELLFMT_FN}"
 
 echo "MACHINE: ${MACHINE}"