diff --git a/Makefile b/Makefile
index 1a2163784..648912bd6 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
 CC=gcc
 CFLAGS=-Wall -Wno-pointer-sign -g
 
-parse: parse.c
+parse: parse.c dive.h
 	$(CC) $(CFLAGS) -o parse `xml2-config --cflags` parse.c `xml2-config --libs`
diff --git a/dive.h b/dive.h
new file mode 100644
index 000000000..9fc390867
--- /dev/null
+++ b/dive.h
@@ -0,0 +1,114 @@
+#ifndef DIVE_H
+#define DIVE_H
+
+/*
+ * Some silly typedefs to make our units very explicit.
+ *
+ * Also, the units are chosen so that values can be expressible as
+ * integers, so that we never have FP rounding issues. And they
+ * are small enough that converting to/from imperial units doesn't
+ * really matter.
+ *
+ * We also strive to make '0' a meaningless number saying "not
+ * initialized", since many values are things that may not have
+ * been reported (eg tank pressure or temperature from dive
+ * computers that don't support them). But sometimes -1 is an even
+ * more explicit way of saying "not there".
+ *
+ * Thus "millibar" for pressure, for example, or "millikelvin" for
+ * temperatures. Doing temperatures in celsius or fahrenheit would
+ * make for loss of precision when converting from one to the other,
+ * and using millikelvin is SI-like but also means that a temperature
+ * of '0' is clearly just a missing temperature or tank pressure.
+ *
+ * Also strive to use units that can not possibly be mistaken for a
+ * valid value in a "normal" system without conversion. If the max
+ * depth of a dive is '20000', you probably didn't convert from mm on
+ * output, or if the max depth gets reported as "0.2ft" it was either
+ * a really boring dive, or there was some missing input conversion,
+ * and a 60-ft dive got recorded as 60mm.
+ *
+ * Doing these as "structs containing value" means that we always
+ * have to explicitly write out those units in order to get at the
+ * actual value. So there is hopefully little fear of using a value
+ * in millikelvin as Fahrenheit by mistake.
+ *
+ * We don't actually use these all yet, so maybe they'll change, but
+ * I made a number of types as guidelines.
+ */
+typedef struct {
+	int seconds;
+} duration_t;
+
+typedef struct {
+	int mm;
+} depth_t;
+
+typedef struct {
+	int mbar;
+} pressure_t;
+
+typedef struct {
+	int mkelvin;
+} temperature_t;
+
+typedef struct {
+	int mliter;
+} volume_t;
+
+typedef struct {
+	int permille;
+} fraction_t;
+
+typedef struct {
+	int grams;
+} weight_t;
+
+typedef struct {
+	fraction_t o2;
+	fraction_t n2;
+	fraction_t he2;
+} gasmix_t;
+
+typedef struct {
+	volume_t size;
+	pressure_t pressure;
+} tank_type_t;
+
+static inline int to_feet(depth_t depth)
+{
+	return depth.mm * 0.00328084 + 0.5;
+}
+
+static inline int to_C(temperature_t temp)
+{
+	if (!temp.mkelvin)
+		return 0;
+	return (temp.mkelvin - 273150) / 1000;
+}
+
+static inline int to_PSI(pressure_t pressure)
+{
+	return pressure.mbar * 0.0145037738 + 0.5;
+}
+
+struct sample {
+	duration_t time;
+	depth_t depth;
+	temperature_t temperature;
+	pressure_t tankpressure;
+	int tankindex;
+};
+
+struct dive {
+	time_t when;
+	depth_t maxdepth, meandepth;
+	duration_t duration, surfacetime;
+	depth_t visibility;
+	temperature_t airtemp, watertemp;
+	pressure_t beginning_pressure, end_pressure;
+	int samples;
+	struct sample sample[];
+};
+
+#endif /* DIVE_H */
diff --git a/parse.c b/parse.c
index 0faf31f81..e3b07c6db 100644
--- a/parse.c
+++ b/parse.c
@@ -7,118 +7,10 @@
 #include <libxml/parser.h>
 #include <libxml/tree.h>
 
+#include "dive.h"
+
 static int verbose;
 
-/*
- * Some silly typedefs to make our units very explicit.
- *
- * Also, the units are chosen so that values can be expressible as
- * integers, so that we never have FP rounding issues. And they
- * are small enough that converting to/from imperial units doesn't
- * really matter.
- *
- * We also strive to make '0' a meaningless number saying "not
- * initialized", since many values are things that may not have
- * been reported (eg tank pressure or temperature from dive
- * computers that don't support them). But sometimes -1 is an even
- * more explicit way of saying "not there".
- *
- * Thus "millibar" for pressure, for example, or "millikelvin" for
- * temperatures. Doing temperatures in celsius or fahrenheit would
- * make for loss of precision when converting from one to the other,
- * and using millikelvin is SI-like but also means that a temperature
- * of '0' is clearly just a missing temperature or tank pressure.
- *
- * Also strive to use units that can not possibly be mistaken for a
- * valid value in a "normal" system without conversion. If the max
- * depth of a dive is '20000', you probably didn't convert from mm on
- * output, or if the max depth gets reported as "0.2ft" it was either
- * a really boring dive, or there was some missing input conversion,
- * and a 60-ft dive got recorded as 60mm.
- *
- * Doing these as "structs containing value" means that we always
- * have to explicitly write out those units in order to get at the
- * actual value. So there is hopefully little fear of using a value
- * in millikelvin as Fahrenheit by mistake.
- *
- * We don't actually use these all yet, so maybe they'll change, but
- * I made a number of types as guidelines.
- */
-typedef struct {
-	int seconds;
-} duration_t;
-
-typedef struct {
-	int mm;
-} depth_t;
-
-typedef struct {
-	int mbar;
-} pressure_t;
-
-typedef struct {
-	int mkelvin;
-} temperature_t;
-
-typedef struct {
-	int mliter;
-} volume_t;
-
-typedef struct {
-	int permille;
-} fraction_t;
-
-typedef struct {
-	int grams;
-} weight_t;
-
-typedef struct {
-	fraction_t o2;
-	fraction_t n2;
-	fraction_t he2;
-} gasmix_t;
-
-typedef struct {
-	volume_t size;
-	pressure_t pressure;
-} tank_type_t;
-
-static int to_feet(depth_t depth)
-{
-	return depth.mm * 0.00328084 + 0.5;
-}
-
-static int to_C(temperature_t temp)
-{
-	if (!temp.mkelvin)
-		return 0;
-	return (temp.mkelvin - 273150) / 1000;
-}
-
-static int to_PSI(pressure_t pressure)
-{
-	return pressure.mbar * 0.0145037738 + 0.5;
-}
-
-struct sample {
-	duration_t time;
-	depth_t depth;
-	temperature_t temperature;
-	pressure_t tankpressure;
-	int tankindex;
-};
-
-struct dive {
-	time_t when;
-	depth_t maxdepth, meandepth;
-	duration_t duration, surfacetime;
-	depth_t visibility;
-	temperature_t airtemp, watertemp;
-	pressure_t beginning_pressure, end_pressure;
-	int samples;
-	struct sample sample[];
-};
-
 static struct dive **dive_table;
 static int nr_dives, nr_allocated;
 
@@ -686,7 +578,7 @@ static void traverse(xmlNode *node)
 	}
 }
 
-static void parse(const char *filename)
+static void parse_xml_file(const char *filename)
 {
 	xmlDoc *doc;
 
@@ -732,7 +624,7 @@ int main(int argc, char **argv)
 			parse_argument(a);
 			continue;
 		}
-		parse(a);
+		parse_xml_file(a);
 	}
 	report_dives();
 	return 0;