diff --git a/ChangeLog b/ChangeLog
index af76a74d1..03d203dfe 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -9,6 +9,9 @@
  * src/document.c, src/keyfile.c, src/search.c, src/tools.c,
    src/utils.c, src/vte.c, tagmanager/tm_source_file.c:
    Replace remaining occurrences of '__func__' with 'G_STRFUNC'.
+ * plugins/geanyfunctions.h, src/dialogs.c, src/plugindata.h,
+   src/plugins.c:
+   Add dialogs_show_input_numeric() to the plugins API.
 
 
 2009-01-20  Nick Treleaven  <nick(dot)treleaven(at)btinternet(dot)com>
diff --git a/plugins/geanyfunctions.h b/plugins/geanyfunctions.h
index 6a651d2b4..b0244ff59 100644
--- a/plugins/geanyfunctions.h
+++ b/plugins/geanyfunctions.h
@@ -190,6 +190,8 @@
 	geany_functions->p_dialogs->show_msgbox
 #define dialogs_show_save_as \
 	geany_functions->p_dialogs->show_save_as
+#define dialogs_show_input_numeric \
+	geany_functions->p_dialogs->show_input_numeric
 #define msgwin_status_add \
 	geany_functions->p_msgwin->status_add
 #define msgwin_compiler_add \
diff --git a/src/dialogs.c b/src/dialogs.c
index 6d86e0242..faa30eb1f 100644
--- a/src/dialogs.c
+++ b/src/dialogs.c
@@ -924,12 +924,30 @@ dialogs_show_input(const gchar *title, const gchar *label_text, const gchar *def
 }
 
 
+/**
+ *  Show an input box to enter a numerical value using a GtkSpinButton.
+ *
+ *  @param title The dialog title.
+ *  @param label_text The shown dialog label.
+ *  @param value The default value for the spin button and the return location of the entered value.
+ * 				 Must be non-NULL.
+ *  @param min Minimum allowable value (see documentation for @a gtk_spin_button_new_with_range()).
+ *  @param max Maximum allowable value (see documentation for @a gtk_spin_button_new_with_range()).
+ *  @param step Increment added or subtracted by spinning the widget
+ * 				(see documentation for @a gtk_spin_button_new_with_range()).
+ *
+ *  @return @a TRUE if a value was entered and the dialog closed with 'OK'. @a FALSE otherwise.
+ **/
 gboolean dialogs_show_input_numeric(const gchar *title, const gchar *label_text,
 									gdouble *value, gdouble min, gdouble max, gdouble step)
 {
 	GtkWidget *dialog, *label, *spin, *vbox;
 	gboolean res = FALSE;
 
+	g_return_val_if_fail(title != NULL, FALSE);
+	g_return_val_if_fail(label_text != NULL, FALSE);
+	g_return_val_if_fail(value != NULL, FALSE);
+
 	dialog = gtk_dialog_new_with_buttons(title, GTK_WINDOW(main_widgets.window),
 										GTK_DIALOG_DESTROY_WITH_PARENT,
 										GTK_STOCK_CANCEL, GTK_RESPONSE_CANCEL,
diff --git a/src/plugindata.h b/src/plugindata.h
index 5c7b58839..cc447ccfa 100644
--- a/src/plugindata.h
+++ b/src/plugindata.h
@@ -45,7 +45,7 @@
 enum {
 	/** The Application Programming Interface (API) version, incremented
 	 * whenever any plugin data types are modified or appended to. */
-	GEANY_API_VERSION = 127,
+	GEANY_API_VERSION = 128,
 
 	/** The Application Binary Interface (ABI) version, incremented whenever
 	 * existing fields in the plugin data types have to be changed or reordered. */
@@ -393,6 +393,9 @@ typedef struct DialogFuncs
 	gboolean	(*show_question) (const gchar *text, ...);
 	void		(*show_msgbox) (gint type, const gchar *text, ...);
 	gboolean	(*show_save_as) (void);
+	gboolean	(*dialogs_show_input_numeric) (const gchar *title, const gchar *label_text,
+				 gdouble *value, gdouble min, gdouble max, gdouble step);
+
 }
 DialogFuncs;
 
diff --git a/src/plugins.c b/src/plugins.c
index 996cb891f..0035a67da 100644
--- a/src/plugins.c
+++ b/src/plugins.c
@@ -231,7 +231,8 @@ static UIUtilsFuncs uiutils_funcs = {
 static DialogFuncs dialog_funcs = {
 	&dialogs_show_question,
 	&dialogs_show_msgbox,
-	&dialogs_show_save_as
+	&dialogs_show_save_as,
+	&dialogs_show_input_numeric
 };
 
 /* Macro to prevent confusing macro being generated in geanyfunctions.h */