diff --git a/lib/shared-functions.sh b/lib/shared-functions.sh
index 6ca7c21..f1dfafb 100644
--- a/lib/shared-functions.sh
+++ b/lib/shared-functions.sh
@@ -179,12 +179,16 @@ function check_sharelatex_env_vars() {
 
 function read_variable() {
   local name=$1
-  grep -E "^$name=" "$TOOLKIT_ROOT/config/variables.env" \
-  | sed -r "s/^$name=([\"']?)(.+)\1\$/\2/"
+  (
+    source "$TOOLKIT_ROOT/config/variables.env"
+    echo "${!name:-}"
+  )
 }
 
 function read_configuration() {
   local name=$1
-  grep -E "^$name=" "$TOOLKIT_ROOT/config/overleaf.rc" \
-  | sed -r "s/^$name=([\"']?)(.+)\1\$/\2/"
+  (
+    source "$TOOLKIT_ROOT/config/overleaf.rc"
+    echo "${!name:-}"
+  )
 }