diff --git a/build/cmake/FindResSearch.cmake b/build/cmake/FindResSearch.cmake
index fcd791b..346f715 100644
--- a/build/cmake/FindResSearch.cmake
+++ b/build/cmake/FindResSearch.cmake
@@ -2,7 +2,7 @@ include (CheckSymbolExists)
 
 if (ENABLE_SRV STREQUAL ON OR ENABLE_SRV STREQUAL AUTO)
    if (WIN32)
-      set (RESOLV_LIBRARIES Dnsapi)
+      set (RESOLV_LIBRARIES dnsapi)
       set (MONGOC_HAVE_DNSAPI 1)
       set (MONGOC_HAVE_RES_NSEARCH 0)
       set (MONGOC_HAVE_RES_NDESTROY 0)
diff --git a/src/libmongoc/CMakeLists.txt b/src/libmongoc/CMakeLists.txt
index 2e1f854..95e6b6b 100644
--- a/src/libmongoc/CMakeLists.txt
+++ b/src/libmongoc/CMakeLists.txt
@@ -688,7 +688,7 @@ if (NOT ENABLE_SSL STREQUAL OFF)
          ${PROJECT_SOURCE_DIR}/src/mongoc/mongoc-stream-tls-secure-channel.c
          ${PROJECT_SOURCE_DIR}/src/mongoc/mongoc-secure-channel.c
       )
-      set (SSL_LIBRARIES secur32.lib crypt32.lib Bcrypt.lib)
+      set (SSL_LIBRARIES secur32.lib crypt32.lib bcrypt.lib)
    elseif (LIBRESSL)
       message (STATUS "Compiling against LibreSSL")
       set (SOURCES ${SOURCES}
@@ -714,7 +714,7 @@ if (MONGOC_ENABLE_SASL)
       message (STATUS "Compiling against Windows SSPI")
       set (SOURCES ${SOURCES} ${PROJECT_SOURCE_DIR}/src/mongoc/mongoc-cluster-sspi.c)
       set (SOURCES ${SOURCES} ${PROJECT_SOURCE_DIR}/src/mongoc/mongoc-sspi.c)
-      set (SASL_LIBRARIES secur32.lib crypt32.lib Shlwapi.lib)
+      set (SASL_LIBRARIES secur32.lib crypt32.lib shlwapi.lib)
    endif ()
 else ()
    message (STATUS "SASL disabled")
diff --git a/src/libmongoc/src/mongoc/mongoc-client.c b/src/libmongoc/src/mongoc/mongoc-client.c
index 457c841..7b6d585 100644
--- a/src/libmongoc/src/mongoc/mongoc-client.c
+++ b/src/libmongoc/src/mongoc/mongoc-client.c
@@ -19,8 +19,8 @@
 #include "mongoc-config.h"
 #ifdef MONGOC_HAVE_DNSAPI
 /* for DnsQuery_UTF8 */
-#include <Windows.h>
-#include <WinDNS.h>
+#include <windows.h>
+#include <windns.h>
 #include <ws2tcpip.h>
 #else
 #if defined(MONGOC_HAVE_RES_NSEARCH) || defined(MONGOC_HAVE_RES_SEARCH)
diff --git a/src/libmongoc/src/mongoc/mongoc-socket.c b/src/libmongoc/src/mongoc/mongoc-socket.c
index e085adb..592bc89 100644
--- a/src/libmongoc/src/mongoc/mongoc-socket.c
+++ b/src/libmongoc/src/mongoc/mongoc-socket.c
@@ -25,7 +25,7 @@
 #include "mongoc-socket-private.h"
 #include "mongoc-trace-private.h"
 #ifdef _WIN32
-#include <Mstcpip.h>
+#include <mstcpip.h>
 #include <process.h>
 #endif
 
diff --git a/src/libmongoc/src/mongoc/mongoc-sspi-private.h b/src/libmongoc/src/mongoc/mongoc-sspi-private.h
index 60996fc..3745eff 100644
--- a/src/libmongoc/src/mongoc/mongoc-sspi-private.h
+++ b/src/libmongoc/src/mongoc/mongoc-sspi-private.h
@@ -28,7 +28,7 @@ BSON_BEGIN_DECLS
 
 #define SECURITY_WIN32 1 /* Required for SSPI */
 
-#include <Windows.h>
+#include <windows.h>
 #include <limits.h>
 #include <sspi.h>
 #include <string.h>