diff --git a/crypto/pkcs7/pkcs7.h b/crypto/pkcs7/pkcs7.h
index 80c725dcd5..197b257725 100644
--- a/crypto/pkcs7/pkcs7.h
+++ b/crypto/pkcs7/pkcs7.h
@@ -66,6 +66,11 @@ extern "C" {
 #include <openssl/bio.h>
 #include <openssl/x509.h>
 
+#ifdef WIN32
+/* Under Win32 this is defined in wincrypt.h */
+#undef PKCS7_ISSUER_AND_SERIAL
+#endif
+
 /*
 Encryption_ID		DES-CBC
 Digest_ID		MD5
diff --git a/crypto/x509/x509.h b/crypto/x509/x509.h
index 6f8fac0c8b..de574791f7 100644
--- a/crypto/x509/x509.h
+++ b/crypto/x509/x509.h
@@ -86,6 +86,12 @@ extern "C" {
 
 #include <openssl/evp.h>
 
+
+#ifdef WIN32
+/* Under Win32 this is defined in wincrypt.h */
+#undef X509_NAME
+#endif
+
 #define X509_FILETYPE_PEM	1
 #define X509_FILETYPE_ASN1	2
 #define X509_FILETYPE_DEFAULT	3
diff --git a/e_os.h b/e_os.h
index bbb1c304d6..b8d053bda5 100644
--- a/e_os.h
+++ b/e_os.h
@@ -103,9 +103,6 @@ extern "C" {
 #ifdef WIN32
 #define get_last_sys_error()	GetLastError()
 #define clear_sys_error()	SetLastError(0)
-/* These are defined in wincrypt.h and can cause problems */
-#undef X509_NAME
-#undef PKCS7_SIGNER_INFO
 #if !defined(WINNT)
 #define WIN_CONSOLE_BUG
 #endif