diff --git a/ggml.h b/ggml.h
index 2037ae24e..a75116ea8 100644
--- a/ggml.h
+++ b/ggml.h
@@ -777,10 +777,13 @@ int ggml_cpu_has_vsx(void);
 // threading for non posix systems
 //
 #ifndef _POSIX_THREADS
+#if defined(_WIN32)
+#include <windows.h>
+#endif
 typedef HANDLE pthread_t;
 typedef DWORD thread_ret_t;
-int pthread_create(pthread_t* out, void* unused, thread_ret_t(*func)(void*), void* arg);
-int pthread_join(pthread_t thread, void* unused);
+static int pthread_create(pthread_t* out, void* unused, thread_ret_t(*func)(void*), void* arg);
+static int pthread_join(pthread_t thread, void* unused);
 #endif
 
 #ifdef  __cplusplus