diff --git a/src/libmongoc/CMakeLists.txt b/src/libmongoc/CMakeLists.txt
index 9b2c2f845d..64bdc251bb 100644
--- a/src/libmongoc/CMakeLists.txt
+++ b/src/libmongoc/CMakeLists.txt
@@ -204,7 +204,7 @@ endfunction()
 # Per-backend link libs/options:
 set(SecureTransport/LINK_LIBRARIES "-framework CoreFoundation" "-framework Security")
 set(SecureTransport/pkg_config_LIBS -framework Corefoundation -framework Security)
-set(SecureChannel/LINK_LIBRARIES secur32.lib crypt32.lib Bcrypt.lib ncrypt.lib)
+set(SecureChannel/LINK_LIBRARIES secur32.lib crypt32.lib bcrypt.lib ncrypt.lib)
 set(SecureChannel/pkg_config_LIBS ${SecureChannel/LINK_LIBRARIES})
 set(OpenSSL/LINK_LIBRARIES OpenSSL::SSL OpenSSL::Crypto $<$<PLATFORM_ID:Windows>:crypt32.lib>)
 set(OpenSSL/pkg_config_LIBS -lssl -lcrypto $<$<PLATFORM_ID:Windows>:crypt32.lib>)
@@ -338,7 +338,7 @@ function(_use_sasl libname)
    target_link_libraries(_mongoc-dependencies INTERFACE _mongoc-sasl_backend)
    install(TARGETS _mongoc-sasl_backend EXPORT mongoc-targets)
    if(libname STREQUAL "SSPI")
-      target_link_libraries(_mongoc-sasl_backend INTERFACE secur32.lib crypt32.lib Shlwapi.lib)
+      target_link_libraries(_mongoc-sasl_backend INTERFACE secur32.lib crypt32.lib shlwapi.lib)
       set(backend "SSPI")
    elseif(libname STREQUAL "CYRUS")
       find_package(SASL2 2.0 REQUIRED)
diff --git a/src/libmongoc/src/mongoc/mongoc-client.c b/src/libmongoc/src/mongoc/mongoc-client.c
index f4322798c0..cf01aa86c2 100644
--- a/src/libmongoc/src/mongoc/mongoc-client.c
+++ b/src/libmongoc/src/mongoc/mongoc-client.c
@@ -20,8 +20,8 @@
 
 #ifdef MONGOC_HAVE_DNSAPI
 /* for DnsQuery_UTF8 */
-#include <WinDNS.h>
-#include <Windows.h>
+#include <winDNS.h>
+#include <windows.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 9231df1a12..440c109af2 100644
--- a/src/libmongoc/src/mongoc/mongoc-socket.c
+++ b/src/libmongoc/src/mongoc/mongoc-socket.c
@@ -23,7 +23,7 @@
 #include <mongoc/mongoc-host-list.h>
 
 #ifdef _WIN32
-#include <Mstcpip.h>
+#include <mstcpip.h>
 #include <process.h>
 #endif
 #include <mlib/cmp.h>
diff --git a/src/libmongoc/src/mongoc/mongoc-sspi-private.h b/src/libmongoc/src/mongoc/mongoc-sspi-private.h
index e5c8c970bd..83185cc50d 100644
--- a/src/libmongoc/src/mongoc/mongoc-sspi-private.h
+++ b/src/libmongoc/src/mongoc/mongoc-sspi-private.h
@@ -29,8 +29,8 @@ BSON_BEGIN_DECLS
 
 #define SECURITY_WIN32 1 /* Required for SSPI */
 
-#include <Windows.h>
 #include <sspi.h>
+#include <windows.h>
 
 #include <limits.h>
 #include <string.h>