diff --git a/lib/constants.sh b/lib/constants.sh
index 23407e3..3047fd5 100644
--- a/lib/constants.sh
+++ b/lib/constants.sh
@@ -5,6 +5,10 @@
 # Repository: https://github.com/eth-p/bat-extras
 # Issues:     https://github.com/eth-p/bat-extras/issues
 # -----------------------------------------------------------------------------
+if [[ -z "$__LIB_CONSTANTS_INITIALIZED" ]]; then
+__LIB_CONSTANTS_INITIALIZED=true
+
+# Constants
 EXECUTABLE_BAT="bat"
 EXECUTABLE_GIT="git"
 EXECUTABLE_DELTA="delta"
@@ -18,3 +22,5 @@ PROGRAM_VERSION="$({
 		printf "%s-git (%s)" "" "$(git -C "${TOP}" rev-parse --short HEAD)"
 	fi
 })"
+
+fi