diff --git a/pkl-core/src/main/java/org/pkl/core/stdlib/base/StringNodes.java b/pkl-core/src/main/java/org/pkl/core/stdlib/base/StringNodes.java
index b34e6bdf..9b07f2af 100644
--- a/pkl-core/src/main/java/org/pkl/core/stdlib/base/StringNodes.java
+++ b/pkl-core/src/main/java/org/pkl/core/stdlib/base/StringNodes.java
@@ -169,6 +169,7 @@ public final class StringNodes {
 
   public abstract static class isGlobPattern extends ExternalPropertyNode {
     @Specialization
+    @TruffleBoundary
     protected boolean eval(String self) {
       try {
         GlobResolver.toRegexString(self);