diff --git a/histogram.cpp b/histogram.cpp
index 76437f7..e43d6aa 100644
--- a/histogram.cpp
+++ b/histogram.cpp
@@ -5,7 +5,7 @@
 #include "histogram.h"
 using namespace std;
 
-static
+void
 find_minmax(vector<double> numbers, double &min, double &max)
 {
     min = numbers[0];