diff --git a/fuzz/main.c b/fuzz/main.c
index 7bd11ce..6e7c1d3 100644
--- a/fuzz/main.c
+++ b/fuzz/main.c
@@ -41,6 +41,11 @@
 #include <errno.h>
 #include <sys/stat.h>
 
+#if defined (_MSC_VER) && ! defined (ssize_t)
+#include <basetsd.h>
+typedef SSIZE_T ssize_t;
+#endif
+
 #include "fuzzer.h"
 
 #if defined (TEST_RUN) && defined (HAVE_FMEMOPEN)
diff --git a/src/psl.c b/src/psl.c
index ddfd37c..1bdba3b 100644
--- a/src/psl.c
+++ b/src/psl.c
@@ -56,6 +56,11 @@
 # include <unistd.h>
 #endif
 
+#if defined(_MSC_VER) && ! defined(ssize_t)
+# include <basetsd.h>
+typedef SSIZE_T ssize_t;
+#endif
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>