diff --git a/lib/Makefile.m32 b/lib/Makefile.m32
index f42a07fdb..b10106653 100644
--- a/lib/Makefile.m32
+++ b/lib/Makefile.m32
@@ -29,7 +29,9 @@ INCLUDES = -I. -I../include
 CFLAGS = -g -O2 -DMINGW32 -DBUILDING_LIBCURL -DHAVE_LONGLONG
 ifdef SSL
   INCLUDES += -I"$(OPENSSL_PATH)/outinc" -I"$(OPENSSL_PATH)/outinc/openssl"
-  CFLAGS += -DUSE_SSLEAY -DHAVE_OPENSSL_ENGINE_H
+  CFLAGS += -DUSE_SSLEAY -DUSE_OPENSSL -DHAVE_OPENSSL_ENGINE_H -DHAVE_OPENSSL_PKCS12_H \
+            -DHAVE_ENGINE_LOAD_BUILTIN_ENGINES -DOPENSSL_NO_KRB5 \
+            -DCURL_CA_BUNDLE='getenv("CURL_CA_BUNDLE")'
   DLL_LIBS = -L$(OPENSSL_PATH)/out -leay32 -lssl32
 endif
 ifdef ZLIB