diff --git a/core/src/main/java/lucee/runtime/functions/system/GetTempFile.java b/core/src/main/java/lucee/runtime/functions/system/GetTempFile.java
index ef7108ed5d..36081ea295 100644
--- a/core/src/main/java/lucee/runtime/functions/system/GetTempFile.java
+++ b/core/src/main/java/lucee/runtime/functions/system/GetTempFile.java
@@ -33,12 +33,18 @@
 
 public final class GetTempFile implements Function {
 	public static String call(PageContext pc, String strDir, String prefix) throws PageException {
+		return call(pc, strDir, prefix, ".tmp");
+	}
+
+	public static String call(PageContext pc, String strDir, String prefix, String extension) throws PageException {
 		Resource dir = ResourceUtil.toResourceExisting(pc, strDir);
 		pc.getConfig().getSecurityManager().checkFileLocation(dir);
 		if (!dir.isDirectory()) throw new ExpressionException("[" + strDir + "] is not a directory");
 		int count = 1;
 		Resource file;
-		while ((file = dir.getRealResource(prefix + pc.getId() + count + ".tmp")).exists()) {
+		if (extension.trim().isEmpty() == true) { extension = ".tmp"; }
+		if (extension.charAt(0) != '.') { extension = "." + extension; }
+		while ((file = dir.getRealResource(prefix + pc.getId() + count + extension)).exists()) {
 			count++;
 		}
 		try {
diff --git a/core/src/main/java/resource/fld/core-base.fld b/core/src/main/java/resource/fld/core-base.fld
index 28e132d30d..4b921dd5a6 100755
--- a/core/src/main/java/resource/fld/core-base.fld
+++ b/core/src/main/java/resource/fld/core-base.fld
@@ -6582,6 +6582,14 @@ if this attribute is not provided all types are returned.</description>
 			<required>Yes</required>
 		<description>Prefix of a temporary file to create in the dir directory</description>
     </argument>
+	<argument>
+    		<name>extension</name>
+			<alias>ext</alias>
+    		<type>string</type>
+			<required>No</required>
+			<Default>tmp</Default>
+		<description>Creates temporary files with user defined extension, default is .tmp</description>
+	</argument>
 		<return>
 			<type>string</type>
 		</return>