diff --git a/stack.go b/stack.go
index fa35098..328c8db 100644
--- a/stack.go
+++ b/stack.go
@@ -33,14 +33,33 @@ func (s *Stack) Push(val VarValue) {
 		s.Values = s.Values[1:]
 	}
 
+	if s.Max == nil {
+		s.Max = val
+		return
+	}
+
 	switch val.(type) {
 	case int64:
-		if s.Max == nil || val.(int64) > s.Max.(int64) {
-			s.Max = val
+		switch s.Max.(type) {
+		case int64:
+			if val.(int64) > s.Max.(int64) {
+				s.Max = val
+			}
+		case float64:
+			if float64(val.(int64)) > s.Max.(float64) {
+				s.Max = val
+			}
 		}
 	case float64:
-		if s.Max == nil || val.(float64) > s.Max.(float64) {
-			s.Max = val
+		switch s.Max.(type) {
+		case int64:
+			if val.(float64) > float64(s.Max.(int64)) {
+				s.Max = val
+			}
+		case float64:
+			if val.(float64) > s.Max.(float64) {
+				s.Max = val
+			}
 		}
 	}
 }
diff --git a/stack_test.go b/stack_test.go
index a028d59..b57f1d3 100644
--- a/stack_test.go
+++ b/stack_test.go
@@ -2,6 +2,20 @@ package main
 
 import "testing"
 
+func TestPushWithFloatAndIntValue(t *testing.T) {
+	s := NewStack()
+	s.Push(VarValue(int64(0.0))) // from service.go:guessValue
+	s.Push(VarValue(5.0))
+	s.Push(VarValue(float64(15.0)))
+	if _, ok := s.Max.(float64); !ok {
+		t.Fatalf("Expected Max to be float64, but it's not")
+	}
+	s.Push(VarValue(int64(25.0)))
+	if _, ok := s.Max.(int64); !ok {
+		t.Fatalf("Expected Max to be int64, but it's not")
+	}
+}
+
 func TestStack(t *testing.T) {
 	size := 10
 	s := NewStackWithSize(size)