diff --git a/src/Make_mvc.mak b/src/Make_mvc.mak
index 5583ef2..c5c0a12 100644
--- a/src/Make_mvc.mak
+++ b/src/Make_mvc.mak
@@ -826,6 +826,11 @@
 
 PERL_EXE = $(PERL)\Bin$(PERL_ARCH)\perl
 PERL_INC = /I $(PERL_INCDIR)
+!if $(MSVC_MAJOR) <= 11
+# ActivePerl 5.20+ requires stdbool.h but VC2012 or earlier doesn't have it.
+# Use a stub stdbool.h.
+PERL_INC = $(PERL_INC) /I if_perl_msvc
+!endif
 PERL_OBJ = $(OUTDIR)\if_perl.obj $(OUTDIR)\if_perlsfio.obj
 XSUBPP = $(PERL)\lib\ExtUtils\xsubpp
 !if exist($(XSUBPP))