diff --git a/core/combo/HOST_windows-x86.mk b/core/combo/HOST_windows-x86.mk
index b71ac16..5839e73 100644
--- a/core/combo/HOST_windows-x86.mk
+++ b/core/combo/HOST_windows-x86.mk
@@ -41,7 +41,9 @@
 
 # Workaround differences in inttypes.h between host and target.
 # See bug 12708004.
-$(combo_2nd_arch_prefix)HOST_GLOBAL_CFLAGS += -D__STDC_FORMAT_MACROS -D__STDC_CONSTANT_MACROS -D__USE_MINGW_ANSI_STDIO
+$(combo_2nd_arch_prefix)HOST_GLOBAL_CFLAGS += -D__STDC_FORMAT_MACROS -D__STDC_CONSTANT_MACROS
+# Use C99-compliant printf functions (%zd).
+$(combo_2nd_arch_prefix)HOST_GLOBAL_CFLAGS += -D__USE_MINGW_ANSI_STDIO=1
 
 $(combo_2nd_arch_prefix)HOST_CC := $(TOOLS_PREFIX)gcc$(TOOLS_EXE_SUFFIX)
 $(combo_2nd_arch_prefix)HOST_CXX := $(TOOLS_PREFIX)g++$(TOOLS_EXE_SUFFIX)
diff --git a/core/combo/HOST_windows-x86_64.mk b/core/combo/HOST_windows-x86_64.mk
index bd392ea..c526f20 100644
--- a/core/combo/HOST_windows-x86_64.mk
+++ b/core/combo/HOST_windows-x86_64.mk
@@ -36,7 +36,9 @@
 
 # Workaround differences in inttypes.h between host and target.
 # See bug 12708004.
-HOST_GLOBAL_CFLAGS += -D__STDC_FORMAT_MACROS -D__STDC_CONSTANT_MACROS -D__USE_MINGW_ANSI_STDIO
+HOST_GLOBAL_CFLAGS += -D__STDC_FORMAT_MACROS -D__STDC_CONSTANT_MACROS
+# Use C99-compliant printf functions (%zd).
+HOST_GLOBAL_CFLAGS += -D__USE_MINGW_ANSI_STDIO=1
 
 HOST_CC := $(TOOLS_PREFIX)gcc$(TOOLS_EXE_SUFFIX)
 HOST_CXX := $(TOOLS_PREFIX)g++$(TOOLS_EXE_SUFFIX)