diff --git a/src/main/java/foundation/identity/jsonld/JsonLDObject.java b/src/main/java/foundation/identity/jsonld/JsonLDObject.java
index d0033db..c61f320 100644
--- a/src/main/java/foundation/identity/jsonld/JsonLDObject.java
+++ b/src/main/java/foundation/identity/jsonld/JsonLDObject.java
@@ -88,7 +88,19 @@ public JsonLDObject build() {
 			if (this.base != null) { JsonLDUtils.jsonLdAddAll(this.jsonLdObject, this.base.getJsonObject()); }
 			if (this.defaultContexts) { List<URI> contexts = new ArrayList<>(JsonLDObject.getDefaultJsonLDContexts(this.jsonLdObject.getClass())); if (this.contexts != null) contexts.addAll(this.contexts); if (! contexts.isEmpty()) this.contexts = contexts; }
 			if (this.defaultTypes) { List<String> types = new ArrayList<>(JsonLDObject.getDefaultJsonLDTypes(this.jsonLdObject.getClass())); if (this.types != null) types.addAll(this.types); if (! types.isEmpty()) this.types = types; }
-			if (this.contexts != null) if (this.forceContextsArray) JsonLDUtils.jsonLdAddAsJsonArray(this.jsonLdObject, Keywords.CONTEXT, this.contexts.stream().map(JsonLDUtils::uriToString).collect(Collectors.toList())); else JsonLDUtils.jsonLdAdd(this.jsonLdObject, Keywords.CONTEXT, this.contexts.stream().map(JsonLDUtils::uriToString).collect(Collectors.toList()));
+            if (this.contexts != null) {
+                List<String> existingContexts = this.contexts.stream().map(JsonLDUtils::uriToString).collect(Collectors.toList());
+                if (this.forceContextsArray) {
+                    JsonLDUtils.jsonLdAddAsJsonArray(this.jsonLdObject, Keywords.CONTEXT, existingContexts);
+                } else {
+                    if(this.jsonLdObject.getContexts()==null || this.jsonLdObject.getContexts().isEmpty()){
+                        JsonLDUtils.jsonLdAdd(this.jsonLdObject, Keywords.CONTEXT, existingContexts);
+                    }else{
+                        JsonLDUtils.jsonLdAddAsJsonArray(this.jsonLdObject, Keywords.CONTEXT, existingContexts);
+                    }
+                }
+            }
+
 			if (this.types != null) if (this.forceTypesArray) JsonLDUtils.jsonLdAddAsJsonArray(this.jsonLdObject, JsonLDKeywords.JSONLD_TERM_TYPE, this.types); else JsonLDUtils.jsonLdAdd(this.jsonLdObject, JsonLDKeywords.JSONLD_TERM_TYPE, this.types);
 			if (this.id != null) JsonLDUtils.jsonLdAdd(this.jsonLdObject, JsonLDKeywords.JSONLD_TERM_ID, JsonLDUtils.uriToString(this.id));
 			if (this.properties != null) JsonLDUtils.jsonLdAddAll(this.jsonLdObject, this.properties);