diff --git a/sparql-anything-engine/src/main/java/io/github/sparqlanything/engine/functions/reflection/Converters.java b/sparql-anything-engine/src/main/java/io/github/sparqlanything/engine/functions/reflection/Converters.java
index d602633d..ea9f8833 100644
--- a/sparql-anything-engine/src/main/java/io/github/sparqlanything/engine/functions/reflection/Converters.java
+++ b/sparql-anything-engine/src/main/java/io/github/sparqlanything/engine/functions/reflection/Converters.java
@@ -54,6 +54,10 @@ public Character asType(NodeValue nodeValue) {
 		public NodeValueString asNodeValue(Character object) {
 			return (NodeValueString) NodeValue.makeNodeString(object.toString());
 		}
+
+		public boolean compatibleWith(NodeValue nodeValue){
+			return nodeValue.getClass().equals(getNodeValueType()) && nodeValue.getString().length() == 1;
+		}
 	}
 
 	public static class StringConverter implements NodeValueConverter<String,NodeValueString> {
diff --git a/sparql-anything-engine/src/test/java/io/github/sparqlanything/engine/test/FunctionsTest.java b/sparql-anything-engine/src/test/java/io/github/sparqlanything/engine/test/FunctionsTest.java
index c8fd5675..0e3b2d8b 100644
--- a/sparql-anything-engine/src/test/java/io/github/sparqlanything/engine/test/FunctionsTest.java
+++ b/sparql-anything-engine/src/test/java/io/github/sparqlanything/engine/test/FunctionsTest.java
@@ -415,6 +415,10 @@ public void testWordUtilsFunctions() {
 		testStringFunction("fx:WordUtils.uncapitalize", WordUtils.uncapitalize("TEST"), "TEST");
 	}
 
+	@Test
+	public void testStringReplace(){
+		testStringFunction("fx:String.replace", "test".replace("te", "fe"), "test", Lists.newArrayList("te", "fe"));
+	}
 	@Test
 	public void testStringFunctions(){
 		testStringFunction("fx:String.trim", " test ".trim(), "test");
@@ -423,8 +427,8 @@ public void testStringFunctions(){
 		testStringFunction("fx:String.indexOf", String.valueOf("test".indexOf("e")), "test", Lists.newArrayList("e"));
 		testStringFunction("fx:String.startsWith", String.valueOf("test".startsWith("te")), "test", Lists.newArrayList("te"));
 		testStringFunction("fx:String.endsWith", String.valueOf("test".endsWith("st")), "test", Lists.newArrayList("st"));
-		testStringFunction("fx:String.replace", "test".replace("te", "fe"), "test", Lists.newArrayList("te", "fe"));
 		testStringFunction("fx:String.replace", "test".replace("t", "f"), "test", Lists.newArrayList("t", "f"));
+		testStringFunction("fx:String.replace", "test".replace("te", "fe"), "test", Lists.newArrayList("te", "fe"));
 		testStringFunction("fx:String.strip", "  test  \t".strip(), "  test  \t");
 		testStringFunction("fx:String.stripLeading", "  test  \t".stripLeading(), "  test  \t");
 		testStringFunction("fx:String.stripTrailing", "  test  \t".stripTrailing(), "  test  \t");