diff --git a/lib/Makefile.m32 b/lib/Makefile.m32
index f3673c5a3..92d59f9b2 100644
--- a/lib/Makefile.m32
+++ b/lib/Makefile.m32
@@ -75,7 +75,7 @@ endif
 endif
 
 ifeq ($(ARCH),w64)
-CFLAGS  += -D_AMD64_
+CFLAGS  += -m64 -D_AMD64_
 RCFLAGS += -F pe-x86-64
 else
 CFLAGS  += -m32
@@ -323,5 +323,3 @@ $(PROOT)/include/curl/curlbuild.h:
 
 $(LIBCARES_PATH)/libcares.a:
 	$(MAKE) -C $(LIBCARES_PATH) -f Makefile.m32
-
-
diff --git a/src/Makefile.m32 b/src/Makefile.m32
index e54175ced..f3f9054f9 100644
--- a/src/Makefile.m32
+++ b/src/Makefile.m32
@@ -90,10 +90,12 @@ endif
 endif
 
 ifeq ($(ARCH),w64)
-CFLAGS	+= -D_AMD64_
+CFLAGS	+= -m64 -D_AMD64_
+LDFLAGS += -m64
 RCFLAGS += -F pe-x86-64
 else
 CFLAGS	+= -m32
+LDFLAGS += -m32
 RCFLAGS += -F pe-i386
 endif
 
@@ -340,4 +342,3 @@ endif
 
 distclean vclean: clean
 	@$(call DEL, $(curl_PROGRAMS))
-