diff --git a/fhirpathpy/engine/invocations/strings.py b/fhirpathpy/engine/invocations/strings.py
index 58997aa..37a47d0 100644
--- a/fhirpathpy/engine/invocations/strings.py
+++ b/fhirpathpy/engine/invocations/strings.py
@@ -125,6 +125,9 @@ def decode(ctx, coll, format):
 
 
 def join(ctx, coll, separator=""):
+    if not coll:
+        return []
+
     stringValues = []
     for n in coll:
         d = util.get_data(n)
diff --git a/tests/cases/5.6_string_manipulation.yaml b/tests/cases/5.6_string_manipulation.yaml
index 4f4de3d..75f164d 100644
--- a/tests/cases/5.6_string_manipulation.yaml
+++ b/tests/cases/5.6_string_manipulation.yaml
@@ -275,6 +275,10 @@ tests:
     expression: "('a'|'b'|'c').join()"
     result: ['abc']
 
+  - desc: '** join on empty input collection'
+    expression: Functions.str.empty.join(',')
+    result: []
+
   - desc: '** join string with date throws error'
     expression: "('a'|'2023-05-28'.toDate()|'c').join(',')"
     error: true