diff --git a/docs/concepts/parsing_evaluation.md b/docs/concepts/parsing_evaluation.md
index f930da11..07cc62b1 100644
--- a/docs/concepts/parsing_evaluation.md
+++ b/docs/concepts/parsing_evaluation.md
@@ -99,7 +99,7 @@ passing it to the _withValues()_ method:
 ```java
 Expression expression = new Expression("(a + b) * (a - b)");
 
-Map<String, Object> values = new HashMap<>();
+Map<String, Double> values = new HashMap<>();
 values.put("a", 3.5);
 values.put("b", 2.5);
 
@@ -111,6 +111,20 @@ System.out.println(result.getNumberValue()); // prints 6.00
 The data conversion of the passed values will automatically be performed through the created
 _EvaluationObject_.
 
+The map can also hold data of different types:
+```java
+Expression expression = new Expression("a+b+c");
+
+Map<String, Object> values = new HashMap<>();
+values.put("a", true);
+values.put("b", " ");
+values.put("c", 24.7);
+
+EvaluationValue result = expression.withValues(values).evaluate();
+
+System.out.println(result.getStringValue()); // prints "true 24.7"
+```
+
 See chapter [Data Types](datatypes.html) for details on the conversion.
 
 Another option to have EvalEx use your data is to define a custom data accessor.
diff --git a/src/main/java/com/ezylang/evalex/Expression.java b/src/main/java/com/ezylang/evalex/Expression.java
index 90ccf2bb..aa9143f1 100644
--- a/src/main/java/com/ezylang/evalex/Expression.java
+++ b/src/main/java/com/ezylang/evalex/Expression.java
@@ -292,8 +292,8 @@ public Expression and(String variable, Object value) {
    * @param values A map with variable values.
    * @return The Expression instance, to allow chaining of methods.
    */
-  public Expression withValues(Map<String, Object> values) {
-    for (Map.Entry<String, Object> entry : values.entrySet()) {
+  public Expression withValues(Map<String, ?> values) {
+    for (Map.Entry<String, ?> entry : values.entrySet()) {
       with(entry.getKey(), entry.getValue());
     }
     return this;
diff --git a/src/test/java/com/ezylang/evalex/ExpressionTest.java b/src/test/java/com/ezylang/evalex/ExpressionTest.java
index ba9cf0b3..4f838a38 100644
--- a/src/test/java/com/ezylang/evalex/ExpressionTest.java
+++ b/src/test/java/com/ezylang/evalex/ExpressionTest.java
@@ -81,6 +81,47 @@ void testWithValues() throws ParseException, EvaluationException {
     assertThat(result.getStringValue()).isEqualTo("6");
   }
 
+  @Test
+  void testWithValuesDoubleMap() throws ParseException, EvaluationException {
+    Expression expression = new Expression("a+b");
+
+    Map<String, Double> values = new HashMap<>();
+    values.put("a", 3.9);
+    values.put("b", 3.1);
+
+    EvaluationValue result = expression.withValues(values).evaluate();
+
+    assertThat(result.getStringValue()).isEqualTo("7");
+  }
+
+  @Test
+  void testWithValuesStringMap() throws ParseException, EvaluationException {
+    Expression expression = new Expression("a+b+c");
+
+    Map<String, String> values = new HashMap<>();
+    values.put("a", "Hello");
+    values.put("b", " ");
+    values.put("c", "world");
+
+    EvaluationValue result = expression.withValues(values).evaluate();
+
+    assertThat(result.getStringValue()).isEqualTo("Hello world");
+  }
+
+  @Test
+  void testWithValuesMixedMap() throws ParseException, EvaluationException {
+    Expression expression = new Expression("a+b+c");
+
+    Map<String, Object> values = new HashMap<>();
+    values.put("a", true);
+    values.put("b", " ");
+    values.put("c", 24.7);
+
+    EvaluationValue result = expression.withValues(values).evaluate();
+
+    assertThat(result.getStringValue()).isEqualTo("true 24.7");
+  }
+
   @Test
   void testDefaultExpressionOwnsOwnConfigurationEntries() {
     Expression expression1 = new Expression("1+1");