diff --git a/histogram.h b/histogram.h
deleted file mode 100644
index 0d8dc8c..0000000
--- a/histogram.h
+++ /dev/null
@@ -1,9 +0,0 @@
-#ifndef HISTOGRAM_H_INCLUDED
-#define HISTOGRAM_H_INCLUDED
-
-#include <vector>
-
-std::vector<size_t>
-make_histogram(const std::vector<double>& numbers, size_t bin_count);
-
-#endif // HISTOGRAM_H_INCLUDED