diff --git a/org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/Utilities.java b/org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/Utilities.java
index 9019581bb..c9075c87b 100644
--- a/org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/Utilities.java
+++ b/org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/Utilities.java
@@ -830,7 +830,7 @@ public class Utilities {
 
 
   public static String encodeUri(String v) {
-    return v.replace(" ", "%20").replace("?", "%3F").replace("=", "%3D").replace("|", "%7C").replace("+", "%2B");
+    return v.replace("%", "%25").replace(" ", "%20").replace("?", "%3F").replace("=", "%3D").replace("|", "%7C").replace("+", "%2B");
   }