diff --git a/install.sh b/install.sh
index dc7a39e..d6f0e17 100755
--- a/install.sh
+++ b/install.sh
@@ -31,7 +31,11 @@ if [ -n "${VERSION:-}" ]; then
   fi
 else
   echo "Fetching latest release..."
-  TAG=$(curl -sSfL "$API" | grep -oP '"tag_name": "\K(.*)(?=")')
+  TAG=$(curl -sSfL "$API" | sed -n 's/.*"tag_name":[[:space:]]*"\([^"]*\)".*/\1/p' | head -n1)
+  if [ -z "$TAG" ]; then
+    echo "Error: could not determine latest release tag"
+    exit 1
+  fi
   echo "Latest version: $TAG"
 fi