diff --git a/src/if_perl_msvc/stdbool.h b/src/if_perl_msvc/stdbool.h
new file mode 100644
index 0000000..de89e3b
--- /dev/null
+++ b/src/if_perl_msvc/stdbool.h
@@ -0,0 +1,3 @@
+/* A stub stdbool.h for VC2012 or earlier.
+ * ActivePerl 5.20+ requires stdbool.h but VC2012 doesn't have it. */
+#define bool char