diff --git a/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/conv40_50/resources40_50/ImplementationGuide40_50.java b/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/conv40_50/resources40_50/ImplementationGuide40_50.java
index 133099991..b2d4e9fc2 100644
--- a/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/conv40_50/resources40_50/ImplementationGuide40_50.java
+++ b/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/conv40_50/resources40_50/ImplementationGuide40_50.java
@@ -2350,7 +2350,7 @@ public class ImplementationGuide40_50 {
           tgt.addParameter(convertImplementationGuideDefinitionParameterComponent(t));
         } else {
           org.hl7.fhir.r4.model.Extension e = new org.hl7.fhir.r4.model.Extension(EXT_IG_DEFINITION_PARAMETER);
-          org.hl7.fhir.r4.model.Extension eCode = new org.hl7.fhir.r4.model.Extension("code", new org.hl7.fhir.r4.model.StringType(t.getCode().getCode()));
+          org.hl7.fhir.r4.model.Extension eCode = new org.hl7.fhir.r4.model.Extension("code", new org.hl7.fhir.r4.model.CodeType(t.getCode().getCode()));
           org.hl7.fhir.r4.model.Extension eValue = new org.hl7.fhir.r4.model.Extension("value", new org.hl7.fhir.r4.model.StringType(t.getValue()));
           e.addExtension(eCode);
           e.addExtension(eValue);
diff --git a/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/conv43_50/resources43_50/ImplementationGuide43_50.java b/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/conv43_50/resources43_50/ImplementationGuide43_50.java
index 139a874dc..d1cbf5d06 100644
--- a/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/conv43_50/resources43_50/ImplementationGuide43_50.java
+++ b/org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/conv43_50/resources43_50/ImplementationGuide43_50.java
@@ -2344,7 +2344,7 @@ public class ImplementationGuide43_50 {
         tgt.addParameter(convertImplementationGuideDefinitionParameterComponent(t));
       else {
         org.hl7.fhir.r4b.model.Extension e = new org.hl7.fhir.r4b.model.Extension(EXT_IG_DEFINITION_PARAMETER);
-        org.hl7.fhir.r4b.model.Extension eCode = new org.hl7.fhir.r4b.model.Extension("code", new org.hl7.fhir.r4b.model.StringType(t.getCode().getCode()));
+        org.hl7.fhir.r4b.model.Extension eCode = new org.hl7.fhir.r4b.model.Extension("code", new org.hl7.fhir.r4b.model.CodeType(t.getCode().getCode()));
         org.hl7.fhir.r4b.model.Extension eValue = new org.hl7.fhir.r4b.model.Extension("value", new org.hl7.fhir.r4b.model.StringType(t.getValue()));
         e.addExtension(eCode);
         e.addExtension(eValue);