diff --git a/org.hl7.fhir.r4/src/main/java/org/hl7/fhir/r4/model/ExpressionNode.java b/org.hl7.fhir.r4/src/main/java/org/hl7/fhir/r4/model/ExpressionNode.java
index 49f66e8fc..60f842147 100644
--- a/org.hl7.fhir.r4/src/main/java/org/hl7/fhir/r4/model/ExpressionNode.java
+++ b/org.hl7.fhir.r4/src/main/java/org/hl7/fhir/r4/model/ExpressionNode.java
@@ -389,7 +389,9 @@ public class ExpressionNode {
 			b.append(")");
 		}
 		if (inner != null) {
-			b.append(".");
+			if (!((ExpressionNode.Kind.Function == inner.getKind()) && (ExpressionNode.Function.Item == inner.getFunction()))) {
+			  b.append(".");
+			}
 			b.append(inner.toString());
 		}
 		if (operation != null) {
diff --git a/org.hl7.fhir.r4/src/main/java/org/hl7/fhir/r4/utils/FHIRPathEngine.java b/org.hl7.fhir.r4/src/main/java/org/hl7/fhir/r4/utils/FHIRPathEngine.java
index b8a9c1cca..1f6a38c6d 100644
--- a/org.hl7.fhir.r4/src/main/java/org/hl7/fhir/r4/utils/FHIRPathEngine.java
+++ b/org.hl7.fhir.r4/src/main/java/org/hl7/fhir/r4/utils/FHIRPathEngine.java
@@ -1080,6 +1080,7 @@ public class FHIRPathEngine {
     case Lower: return checkParamCount(lexer, location, exp, 0);
     case Upper: return checkParamCount(lexer, location, exp, 0);
     case ToChars: return checkParamCount(lexer, location, exp, 0);
+    case IndexOf : return checkParamCount(lexer, location, exp, 1);
     case Substring: return checkParamCount(lexer, location, exp, 1, 2);
     case StartsWith: return checkParamCount(lexer, location, exp, 1);
     case EndsWith: return checkParamCount(lexer, location, exp, 1);
diff --git a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/model/ExpressionNode.java b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/model/ExpressionNode.java
index ad872b3fd..46cde7c49 100644
--- a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/model/ExpressionNode.java
+++ b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/model/ExpressionNode.java
@@ -390,7 +390,9 @@ public class ExpressionNode {
 			b.append(")");
 		}
 		if (inner != null) {
-			b.append(".");
+			if (!((ExpressionNode.Kind.Function == inner.getKind()) && (ExpressionNode.Function.Item == inner.getFunction()))) {
+				b.append(".");
+			}
 			b.append(inner.toString());
 		}
 		if (operation != null) {