diff --git a/CMake/win32-cache.cmake b/CMake/win32-cache.cmake
index 4fe9eb1139..cb2e45cf56 100644
--- a/CMake/win32-cache.cmake
+++ b/CMake/win32-cache.cmake
@@ -191,6 +191,7 @@ if(MINGW OR MSVC)
   curl_prefill_type_size("LONG_LONG" 8)
   curl_prefill_type_size("__INT64" 8)
   curl_prefill_type_size("CURL_OFF_T" 8)
+  curl_prefill_type_size("ADDRESS_FAMILY" 2)  # MSVC or mingw-w64 v2+
   # CURL_SOCKET_T, SIZE_T: 8 for _WIN64, 4 otherwise
   # TIME_T: 8 for _WIN64 or UCRT or MSVC and not Windows CE, 4 otherwise
   #   Also 4 for non-UCRT 32-bit when _USE_32BIT_TIME_T is set.
@@ -199,20 +200,10 @@ if(MINGW OR MSVC)
     set(HAVE_SIZEOF_SSIZE_T 0)
     set(HAVE_FILE_OFFSET_BITS 0)
     curl_prefill_type_size("OFF_T" 4)
-    curl_prefill_type_size("ADDRESS_FAMILY" 2)
   else()
     # SSIZE_T: 8 for _WIN64, 4 otherwise
-    if(MINGW64_VERSION)
-      if(MINGW64_VERSION VERSION_GREATER_EQUAL 3.0)
-        set(HAVE_FILE_OFFSET_BITS 1)
-        curl_prefill_type_size("OFF_T" 8)
-      endif()
-      if(MINGW64_VERSION VERSION_GREATER_EQUAL 2.0)
-        curl_prefill_type_size("ADDRESS_FAMILY" 2)
-      else()
-        set(HAVE_SIZEOF_ADDRESS_FAMILY 0)
-      endif()
-    endif()
+    set(HAVE_FILE_OFFSET_BITS 1)  # mingw-w64 v3+
+    curl_prefill_type_size("OFF_T" 8)  # mingw-w64 v3+
   endif()
 endif()
 
diff --git a/CMakeLists.txt b/CMakeLists.txt
index d113989a5c..f3041b652d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -246,6 +246,9 @@ if(WIN32)
       string(REGEX REPLACE "MINGW64_VERSION=" "" MINGW64_VERSION "${CURL_TEST_OUTPUT}")
       if(MINGW64_VERSION)
         message(STATUS "Found MINGW64_VERSION=${MINGW64_VERSION}")
+        if(MINGW64_VERSION VERSION_LESS 3.0)
+          message(FATAL_ERROR "mingw-w64 3.0 or upper is required")
+        endif()
       endif()
     endif()
     unset(MINGW64_VERSION CACHE)  # Avoid storing in CMake cache
@@ -1595,7 +1598,6 @@ if(WIN32)
   # Pre-fill detection results based on target OS version
   if(_CURL_PREFILL)
     if(NOT HAVE_WIN32_WINNT OR HAVE_WIN32_WINNT LESS 0x0600 OR  # older than Windows Vista
-       (MINGW AND MINGW64_VERSION VERSION_LESS 2.0) OR
        WINCE OR WINDOWS_STORE)
       set(HAVE_IF_NAMETOINDEX 0)
       unset(HAVE_IF_NAMETOINDEX CACHE)
diff --git a/docs/INSTALL.md b/docs/INSTALL.md
index 410fba07d4..0c53731710 100644
--- a/docs/INSTALL.md
+++ b/docs/INSTALL.md
@@ -181,7 +181,7 @@ Building for Windows XP is required as a minimum.
 You can build curl with:
 
 - Microsoft Visual Studio 2008 v9.0 or later (`_MSC_VER >= 1500`)
-- MinGW-w64
+- MinGW-w64 3.0 or later (`__MINGW64_VERSION_MAJOR >= 3`)
 
 ## Building Windows DLLs and C runtime (CRT) linkage issues
 
diff --git a/lib/curl_setup.h b/lib/curl_setup.h
index fc5359d1b4..36da5c6cbf 100644
--- a/lib/curl_setup.h
+++ b/lib/curl_setup.h
@@ -75,6 +75,11 @@
 #endif
 #endif
 
+#if defined(__MINGW32__) && \
+  (!defined(__MINGW64_VERSION_MAJOR) || (__MINGW64_VERSION_MAJOR < 3))
+#error "Building curl requires mingw-w64 3.0 or later"
+#endif
+
 /* Visual Studio 2008 is the minimum Visual Studio version we support.
    Workarounds for older versions of Visual Studio have been removed. */
 #if defined(_MSC_VER) && (_MSC_VER < 1500)
diff --git a/lib/easy_lock.h b/lib/easy_lock.h
index 2d705174be..909753f43a 100644
--- a/lib/easy_lock.h
+++ b/lib/easy_lock.h
@@ -30,12 +30,6 @@
 
 #if defined(_WIN32_WINNT) && _WIN32_WINNT >= 0x600
 
-#ifdef __MINGW32__
-#ifndef SRWLOCK_INIT
-#define SRWLOCK_INIT NULL
-#endif
-#endif /* __MINGW32__ */
-
 #define curl_simple_lock SRWLOCK
 #define CURL_SIMPLE_LOCK_INIT SRWLOCK_INIT