diff --git a/relay/channel/gemini/relay-gemini.go b/relay/channel/gemini/relay-gemini.go
index 8ca9a502d..65e5aa985 100644
--- a/relay/channel/gemini/relay-gemini.go
+++ b/relay/channel/gemini/relay-gemini.go
@@ -675,6 +675,7 @@ func cleanFunctionParameters(params interface{}) interface{} {
 		delete(cleanedMap, "exclusiveMinimum")
 		delete(cleanedMap, "$schema")
 		delete(cleanedMap, "additionalProperties")
+		delete(cleanedMap, "propertyNames")
 
 		// Check and clean 'format' for string types
 		if propType, typeExists := cleanedMap["type"].(string); typeExists && propType == "string" {