diff --git a/CMakeLists.txt b/CMakeLists.txt
index ac3e90903..f73470dff 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -159,6 +159,11 @@ if (NOT TARGET ggml AND NOT LLAMA_USE_SYSTEM_GGML)
     # ... otherwise assume ggml is added by a parent CMakeLists.txt
 endif()
 
+if (MINGW)
+    # Target Windows 8 for PrefetchVirtualMemory
+    add_compile_definitions(_WIN32_WINNT=${GGML_WIN_VER})
+endif()
+
 #
 # build the library
 #
diff --git a/ggml/CMakeLists.txt b/ggml/CMakeLists.txt
index 3d01184a2..e186fdf3c 100644
--- a/ggml/CMakeLists.txt
+++ b/ggml/CMakeLists.txt
@@ -137,7 +137,7 @@ set(GGML_CPU_ARM_ARCH        "" CACHE STRING "ggml: CPU architecture for ARM")
 set(GGML_CPU_POWERPC_CPUTYPE "" CACHE STRING "ggml: CPU type for PowerPC")
 
 
-if (WIN32)
+if (MINGW)
     set(GGML_WIN_VER "0x602" CACHE STRING   "ggml: Windows version")
 endif()
 
diff --git a/ggml/src/CMakeLists.txt b/ggml/src/CMakeLists.txt
index 76b24bd9d..7dcb031f0 100644
--- a/ggml/src/CMakeLists.txt
+++ b/ggml/src/CMakeLists.txt
@@ -125,7 +125,6 @@ if (NOT MSVC)
 endif()
 
 if (MINGW)
-    # Target Windows 8 for PrefetchVirtualMemory
     add_compile_definitions(_WIN32_WINNT=${GGML_WIN_VER})
 endif()
 
diff --git a/src/llama-mmap.cpp b/src/llama-mmap.cpp
index 9da97f1bc..47497cf95 100644
--- a/src/llama-mmap.cpp
+++ b/src/llama-mmap.cpp
@@ -401,7 +401,7 @@ struct llama_mmap::impl {
                 }
             }
 #else
-            throw std::runtime_error("PrefetchVirtualMemory unavailable");
+            LLAMA_LOG_DEBUG("skipping PrefetchVirtualMemory because _WIN32_WINNT < 0x602\n");
 #endif
         }
     }