diff --git a/include/prism/defines.h b/include/prism/defines.h
index f697b9e5547..457a8502f89 100644
--- a/include/prism/defines.h
+++ b/include/prism/defines.h
@@ -1,7 +1,7 @@
 #ifndef PRISM_DEFINES_H
 #define PRISM_DEFINES_H
 
-// This file should be included first by any *.h or *.c in prism
+// This file should be included first by any *.h or *.c in prism.
 
 #include <ctype.h>
 #include <stdarg.h>
diff --git a/include/prism/prettyprint.h b/include/prism/prettyprint.h
index 04596793d47..9ae2397e636 100644
--- a/include/prism/prettyprint.h
+++ b/include/prism/prettyprint.h
@@ -9,7 +9,13 @@
 #include "prism/parser.h"
 #include "prism/util/pm_buffer.h"
 
-// Pretty-prints the AST represented by the given node to the given buffer.
+/**
+ * Pretty-prints the AST represented by the given node to the given buffer.
+ *
+ * @param output_buffer The buffer to write the pretty-printed AST to.
+ * @param parser The parser that parsed the AST.
+ * @param node The root node of the AST to pretty-print.
+ */
 PRISM_EXPORTED_FUNCTION void pm_prettyprint(pm_buffer_t *output_buffer, const pm_parser_t *parser, const pm_node_t *node);
 
 #endif
diff --git a/include/prism/version.h b/include/prism/version.h
index 9a72a1dbdfa..25ee409c74f 100644
--- a/include/prism/version.h
+++ b/include/prism/version.h
@@ -1,4 +1,19 @@
+/**
+ * The major version of the Prism library as an int.
+ */
 #define PRISM_VERSION_MAJOR 0
+
+/**
+ * The minor version of the Prism library as an int.
+ */
 #define PRISM_VERSION_MINOR 16
+
+/**
+ * The patch version of the Prism library as an int.
+ */
 #define PRISM_VERSION_PATCH 0
+
+/**
+ * The version of the Prism library as a constant string.
+ */
 #define PRISM_VERSION "0.16.0"
diff --git a/templates/src/prettyprint.c.erb b/templates/src/prettyprint.c.erb
index 2309a86f1f8..d5bf196e0b5 100644
--- a/templates/src/prettyprint.c.erb
+++ b/templates/src/prettyprint.c.erb
@@ -177,7 +177,9 @@ prettyprint_node(pm_buffer_t *output_buffer, const pm_parser_t *parser, const pm
     }
 }
 
-// Pretty-prints the AST represented by the given node to the given buffer.
+/**
+ * Pretty-prints the AST represented by the given node to the given buffer.
+ */
 PRISM_EXPORTED_FUNCTION void
 pm_prettyprint(pm_buffer_t *output_buffer, const pm_parser_t *parser, const pm_node_t *node) {
     pm_buffer_t prefix_buffer = { 0 };