diff --git a/newgrf_config.c b/newgrf_config.c
index aecdf40550..ac7b60fd5b 100644
--- a/newgrf_config.c
+++ b/newgrf_config.c
@@ -6,6 +6,7 @@
 #include "macros.h"
 #include "debug.h"
 #include "variables.h"
+#include "string.h"
 #include "saveload.h"
 #include "md5.h"
 #include "newgrf.h"
@@ -261,6 +262,22 @@ const GRFConfig *GetGRFConfig(uint32 grfid)
 }
 
 
+/* Build a space separated list of parameters, and terminate */
+char *GRFBuildParamList(char *dst, const GRFConfig *c, const char *last)
+{
+	uint i;
+
+	/* Return an empty string if there are no parameters */
+	if (c->num_params == 0) return strecpy(dst, "", last);
+
+	for (i = 0; i < c->num_params; i++) {
+		if (i > 0) dst = strecpy(dst, " ", last);
+		dst += snprintf(dst, last - dst, "%d", c->param[i]);
+	}
+	return dst;
+}
+
+
 static const SaveLoad _grfconfig_desc[] = {
 	SLE_STR(GRFConfig, filename,   SLE_STR, 0x40),
 	SLE_VAR(GRFConfig, grfid,      SLE_UINT32),
diff --git a/newgrf_config.h b/newgrf_config.h
index 870ace532f..45d0e270da 100644
--- a/newgrf_config.h
+++ b/newgrf_config.h
@@ -40,6 +40,7 @@ void ClearGRFConfigList(GRFConfig *config);
 void ResetGRFConfig(bool defaults);
 bool IsGoodGRFConfigList(void);
 bool FillGRFDetails(GRFConfig *config);
+char *GRFBuildParamList(char *dst, const GRFConfig *c, const char *last);
 
 /* In newgrf_gui.c */
 void ShowNewGRFSettings(bool editable, bool show_params, GRFConfig **config);
diff --git a/newgrf_gui.c b/newgrf_gui.c
index ae14401a92..c2e76a0212 100644
--- a/newgrf_gui.c
+++ b/newgrf_gui.c
@@ -7,28 +7,11 @@
 #include "gfx.h"
 #include "gui.h"
 #include "window.h"
-#include "strings.h"
 #include "table/strings.h"
 #include "table/sprites.h"
 #include "newgrf_config.h"
 
 
-/* Build a space separated list of parameters, and terminate */
-static char *BuildParamList(char *dst, const GRFConfig *c, const char *last)
-{
-	uint i;
-
-	/* Return an empty string if there are no parameters */
-	if (c->num_params == 0) return strecpy(dst, "", last);
-
-	for (i = 0; i < c->num_params; i++) {
-		if (i > 0) dst = strecpy(dst, " ", last);
-		dst += snprintf(dst, last - dst, "%d", c->param[i]);
-	}
-	return dst;
-}
-
-
 /** Parse an integerlist string and set each found value
  * @param p the string to be parsed. Each element in the list is seperated by a
  * comma or a space character
@@ -80,7 +63,7 @@ static void ShowNewGRFInfo(const GRFConfig *c, uint x, uint y, uint w, bool show
 	/* Show GRF parameter list */
 	if (show_params) {
 		if (c->num_params > 0) {
-			BuildParamList(buff, c, lastof(buff));
+			GRFBuildParamList(buff, c, lastof(buff));
 			SetDParamStr(0, buff);
 		} else {
 			SetDParam(0, STR_01A9_NONE);
@@ -401,7 +384,7 @@ static void NewGRFWndProc(Window *w, WindowEvent *e)
 					char buff[512];
 					if (WP(w, newgrf_d).sel == NULL) break;
 
-					BuildParamList(buff, WP(w, newgrf_d).sel, lastof(buff));
+					GRFBuildParamList(buff, WP(w, newgrf_d).sel, lastof(buff));
 					ShowQueryString(BindCString(buff), STR_NEWGRF_PARAMETER_QUERY, 63, 250, w->window_class, w->window_number, CS_ALPHANUMERAL);
 					break;
 				}