diff --git a/gf2pbm.c b/gf2pbm.c
index fa31ea0..1367dc1 100644
--- a/gf2pbm.c
+++ b/gf2pbm.c
@@ -32,6 +32,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #include <string.h>
 #include <unistd.h>		/* getopt. */
 #include <strings.h>
+#include <stdbool.h>
 
 #include "config.h"
 
@@ -106,7 +107,6 @@ BMUNIT	bit_masks[33] = {
 #endif
 #endif
 
-typedef enum {false,true}bool;
 bool debug;
 
 struct font {