diff --git a/lib/curl_ntlm_msgs.c b/lib/curl_ntlm_msgs.c
index b064553c2..4c4dcfde6 100644
--- a/lib/curl_ntlm_msgs.c
+++ b/lib/curl_ntlm_msgs.c
@@ -394,7 +394,7 @@ CURLcode Curl_ntlm_create_type1_message(const char *userp,
   SecBuffer buf;
   SecBufferDesc desc;
   SECURITY_STATUS status;
-  ULONG attrs;
+  unsigned long attrs;
   const char *user;
   const char *domain = "";
   size_t userlen = 0;
@@ -461,7 +461,7 @@ CURLcode Curl_ntlm_create_type1_message(const char *userp,
     ntlm->p_identity = NULL;
 
   status = s_pSecFn->AcquireCredentialsHandle(NULL,
-                                              (SECURITY_PSTR) TEXT("NTLM"),
+                                              (TCHAR *) TEXT("NTLM"),
                                               SECPKG_CRED_OUTBOUND, NULL,
                                               ntlm->p_identity, NULL, NULL,
                                               &ntlm->handle, &tsDummy);
@@ -476,7 +476,7 @@ CURLcode Curl_ntlm_create_type1_message(const char *userp,
   buf.pvBuffer   = ntlmbuf;
 
   status = s_pSecFn->InitializeSecurityContext(&ntlm->handle, NULL,
-                                               (SECURITY_PSTR) TEXT(""),
+                                               (TCHAR *) TEXT(""),
                                                ISC_REQ_CONFIDENTIALITY |
                                                ISC_REQ_REPLAY_DETECT |
                                                ISC_REQ_CONNECTION,
@@ -631,7 +631,7 @@ CURLcode Curl_ntlm_create_type3_message(struct SessionHandle *data,
   SecBufferDesc type_2_desc;
   SecBufferDesc type_3_desc;
   SECURITY_STATUS status;
-  ULONG attrs;
+  unsigned long attrs;
   TimeStamp tsDummy; /* For Windows 9x compatibility of SSPI calls */
 
   (void)passwdp;
@@ -652,7 +652,7 @@ CURLcode Curl_ntlm_create_type3_message(struct SessionHandle *data,
 
   status = s_pSecFn->InitializeSecurityContext(&ntlm->handle,
                                                &ntlm->c_handle,
-                                               (SECURITY_PSTR) TEXT(""),
+                                               (TCHAR *) TEXT(""),
                                                ISC_REQ_CONFIDENTIALITY |
                                                ISC_REQ_REPLAY_DETECT |
                                                ISC_REQ_CONNECTION,
diff --git a/lib/curl_schannel.c b/lib/curl_schannel.c
index 040133824..55fe92a39 100644
--- a/lib/curl_schannel.c
+++ b/lib/curl_schannel.c
@@ -100,7 +100,7 @@ schannel_connect_step1(struct connectdata *conn, int sockindex)
 #ifdef ENABLE_IPV6
   struct in6_addr addr6;
 #endif
-  LPTSTR host_name;
+  TCHAR *host_name;
 
   infof(data, "schannel: connecting to %s:%hu (step 1/3)\n",
         conn->host.name, conn->remote_port);
@@ -263,7 +263,7 @@ schannel_connect_step2(struct connectdata *conn, int sockindex)
   SecBuffer inbuf[2];
   SecBufferDesc inbuf_desc;
   SECURITY_STATUS sspi_status = SEC_E_OK;
-  LPTSTR host_name;
+  TCHAR *host_name;
 
   infof(data, "schannel: connecting to %s:%hu (step 2/3)\n",
         conn->host.name, conn->remote_port);
diff --git a/lib/http_negotiate_sspi.c b/lib/http_negotiate_sspi.c
index 7c8235518..f5e1fed73 100644
--- a/lib/http_negotiate_sspi.c
+++ b/lib/http_negotiate_sspi.c
@@ -89,9 +89,9 @@ int Curl_input_negotiate(struct connectdata *conn, bool proxy,
   SecBuffer         out_sec_buff;
   SecBufferDesc     in_buff_desc;
   SecBuffer         in_sec_buff;
-  ULONG             context_attributes;
+  unsigned long     context_attributes;
   TimeStamp         lifetime;
-  LPTSTR            sname;
+  TCHAR             *sname;
   int ret;
   size_t len = 0, input_token_len = 0;
   bool gss = FALSE;
@@ -138,7 +138,7 @@ int Curl_input_negotiate(struct connectdata *conn, bool proxy,
 
   if(!neg_ctx->output_token) {
     PSecPkgInfo SecurityPackage;
-    ret = s_pSecFn->QuerySecurityPackageInfo((SECURITY_PSTR) TEXT("Negotiate"),
+    ret = s_pSecFn->QuerySecurityPackageInfo((TCHAR *) TEXT("Negotiate"),
                                              &SecurityPackage);
     if(ret != SEC_E_OK)
       return -1;
@@ -168,7 +168,7 @@ int Curl_input_negotiate(struct connectdata *conn, bool proxy,
 
     neg_ctx->status =
       s_pSecFn->AcquireCredentialsHandle(NULL,
-                                         (SECURITY_PSTR) TEXT("Negotiate"),
+                                         (TCHAR *) TEXT("Negotiate"),
                                          SECPKG_CRED_OUTBOUND, NULL, NULL,
                                          NULL, NULL, neg_ctx->credentials,
                                          &lifetime);
diff --git a/lib/idn_win32.c b/lib/idn_win32.c
index 6351f791d..bb483a6ae 100644
--- a/lib/idn_win32.c
+++ b/lib/idn_win32.c
@@ -31,8 +31,8 @@
 #include "curl_multibyte.h"
 
 #ifdef WANT_IDN_PROTOTYPES
-WINBASEAPI int WINAPI IdnToAscii(DWORD, LPCWSTR, int, LPWSTR, int);
-WINBASEAPI int WINAPI IdnToUnicode(DWORD, LPCWSTR, int, LPWSTR, int);
+WINBASEAPI int WINAPI IdnToAscii(DWORD, const WCHAR *, int, WCHAR *, int);
+WINBASEAPI int WINAPI IdnToUnicode(DWORD, const WCHAR *, int, WCHAR *, int);
 #endif
 
 #define IDN_MAX_LENGTH 255
diff --git a/lib/socks_sspi.c b/lib/socks_sspi.c
index a1d82ea76..43e0064a5 100644
--- a/lib/socks_sspi.c
+++ b/lib/socks_sspi.c
@@ -90,7 +90,7 @@ CURLcode Curl_SOCKS5_gssapi_negotiate(int sockindex,
   TimeStamp expiry;
   char *service_name = NULL;
   unsigned short us_length;
-  ULONG qop;
+  unsigned long qop;
   unsigned char socksreq[4]; /* room for gssapi exchange header only */
   char *service = data->set.str[STRING_SOCKS5_GSSAPI_SERVICE];
 
@@ -141,7 +141,7 @@ CURLcode Curl_SOCKS5_gssapi_negotiate(int sockindex,
   cred_handle.dwUpper = 0;
 
   status = s_pSecFn->AcquireCredentialsHandle(NULL,
-                                              (SECURITY_PSTR) TEXT("Kerberos"),
+                                              (TCHAR *) TEXT("Kerberos"),
                                               SECPKG_CRED_OUTBOUND,
                                               NULL,
                                               NULL,
@@ -160,7 +160,7 @@ CURLcode Curl_SOCKS5_gssapi_negotiate(int sockindex,
   /* As long as we need to keep sending some context info, and there's no  */
   /* errors, keep sending it...                                            */
   for(;;) {
-    LPTSTR sname;
+    TCHAR *sname;
 #ifdef UNICODE
     sname = Curl_convert_UTF8_to_wchar(service_name);
     if(!sname)