diff --git a/src/font_sdlttf.c b/src/font_sdlttf.c
index 2f6eb32..dd6086d 100644
--- a/src/font_sdlttf.c
+++ b/src/font_sdlttf.c
@@ -73,6 +73,8 @@ static agsurface_t *font_sdlttf_get_glyph(const unsigned char *msg) {
 	static SDL_Surface *fs;
 	static agsurface_t result;
 
+	if (!fontset)
+		return NULL;
 	if (fs) {
 		SDL_FreeSurface(fs);
 		fs = NULL;
@@ -148,6 +150,8 @@ static int font_sdlttf_draw_glyph(int x, int y, const unsigned char *str, int cl
 	
 	if (!*str)
 		return 0;
+	if (!fontset)
+		return 0;
 	
 	conv = sjis2lang(str);
 	if (this->antialiase_on) {