diff --git a/ptexplain.c b/ptexplain.c
index 1ea569a..b2ec567 100644
--- a/ptexplain.c
+++ b/ptexplain.c
@@ -13,6 +13,7 @@
 #include <ctype.h>
 #include <assert.h>
 #include <getopt.h>
+#include <libgen.h>
 
 #if HAVE_LIBPNG
 # include <png.h>
diff --git a/rastertoptch.c b/rastertoptch.c
index a4f9cf9..0dc4096 100644
--- a/rastertoptch.c
+++ b/rastertoptch.c
@@ -273,6 +273,7 @@
 #include <limits.h>
 #include <stdbool.h>
 #include <getopt.h>
+#include <libgen.h>
 
 static const char* progname;