diff --git a/graph.c b/graph.c
index 7e0a099f832975..e864fe2c6a2137 100644
--- a/graph.c
+++ b/graph.c
@@ -7,6 +7,34 @@
 
 /* Internal API */
 
+/*
+ * Output the next line for a graph.
+ * This formats the next graph line into the specified strbuf.  It is not
+ * terminated with a newline.
+ *
+ * Returns 1 if the line includes the current commit, and 0 otherwise.
+ * graph_next_line() will return 1 exactly once for each time
+ * graph_update() is called.
+ */
+static int graph_next_line(struct git_graph *graph, struct strbuf *sb);
+
+/*
+ * Set up a custom scheme for column colors.
+ *
+ * The default column color scheme inserts ANSI color escapes to colorize
+ * the graph. The various color escapes are stored in an array of strings
+ * where each entry corresponds to a color, except for the last entry,
+ * which denotes the escape for resetting the color back to the default.
+ * When generating the graph, strings from this array are inserted before
+ * and after the various column characters.
+ *
+ * This function allows you to enable a custom array of color escapes.
+ * The 'colors_max' argument is the index of the last "reset" entry.
+ *
+ * This functions must be called BEFORE graph_init() is called.
+ */
+static void graph_set_column_colors(const char **colors, unsigned short colors_max);
+
 /*
  * Output a padding line in the graph.
  * This is similar to graph_next_line().  However, it is guaranteed to
@@ -62,7 +90,7 @@ enum graph_state {
 static const char **column_colors;
 static unsigned short column_colors_max;
 
-void graph_set_column_colors(const char **colors, unsigned short colors_max)
+static void graph_set_column_colors(const char **colors, unsigned short colors_max)
 {
 	column_colors = colors;
 	column_colors_max = colors_max;
@@ -1116,7 +1144,7 @@ static void graph_output_collapsing_line(struct git_graph *graph, struct strbuf
 		graph_update_state(graph, GRAPH_PADDING);
 }
 
-int graph_next_line(struct git_graph *graph, struct strbuf *sb)
+static int graph_next_line(struct git_graph *graph, struct strbuf *sb)
 {
 	switch (graph->state) {
 	case GRAPH_PADDING:
diff --git a/graph.h b/graph.h
index aff960c7e8f63f..19b0f6631654f4 100644
--- a/graph.h
+++ b/graph.h
@@ -4,22 +4,6 @@
 /* A graph is a pointer to this opaque structure */
 struct git_graph;
 
-/*
- * Set up a custom scheme for column colors.
- *
- * The default column color scheme inserts ANSI color escapes to colorize
- * the graph. The various color escapes are stored in an array of strings
- * where each entry corresponds to a color, except for the last entry,
- * which denotes the escape for resetting the color back to the default.
- * When generating the graph, strings from this array are inserted before
- * and after the various column characters.
- *
- * This function allows you to enable a custom array of color escapes.
- * The 'colors_max' argument is the index of the last "reset" entry.
- *
- * This functions must be called BEFORE graph_init() is called.
- */
-void graph_set_column_colors(const char **colors, unsigned short colors_max);
 
 /*
  * Create a new struct git_graph.
@@ -49,17 +33,6 @@ void graph_update(struct git_graph *graph, struct commit *commit);
  */
 int graph_is_commit_finished(struct git_graph const *graph);
 
-/*
- * Output the next line for a graph.
- * This formats the next graph line into the specified strbuf.  It is not
- * terminated with a newline.
- *
- * Returns 1 if the line includes the current commit, and 0 otherwise.
- * graph_next_line() will return 1 exactly once for each time
- * graph_update() is called.
- */
-int graph_next_line(struct git_graph *graph, struct strbuf *sb);
-
 
 /*
  * graph_show_*: helper functions for printing to stdout