diff --git a/Makefile b/Makefile
index 21493ce..1a41f7e 100644
--- a/Makefile
+++ b/Makefile
@@ -1,12 +1,11 @@
 PROG := tdfiglet
 SRC := tdfiglet.c
-CC := cc
+CC ?= cc
 CFLAGS += -std=c99 -Wall
 
 UNAME := $(shell sh -c 'uname -s 2>/dev/null')
 
 ifeq ($(UNAME),Darwin)
-	CC := clang
 	CFLAGS += -Wunused-result -Wunused-value
 	LDFLAGS += -liconv
 endif
diff --git a/tdfiglet.c b/tdfiglet.c
index f91a1ee..2ce73dd 100644
--- a/tdfiglet.c
+++ b/tdfiglet.c
@@ -224,12 +224,20 @@ font_t
 		exit(EX_NOINPUT);
 	}
 
-	stat(fn, &st);
+	if (stat(fn, &st)) {
+		perror(NULL);
+		exit(EX_OSERR);
+	}
 
 	len = st.st_size;
 
 	map = mmap(0, len, PROT_READ, MAP_PRIVATE, fd, 0);
 
+	if (!map) {
+		perror(NULL);
+		exit(EX_OSERR);
+	}
+
 	close(fd);
 
 	if (!font) {
@@ -341,7 +349,6 @@ readchar(int i, glyph_t *glyph, font_t *font)
 			ch = ' ';
 			row++;
 			col = 0;
-			color = 0;
 		} else {
 			color = *p;
 			p++;