diff --git a/library/x509_crt.c b/library/x509_crt.c
index 91d4626..d7723ac 100644
--- a/library/x509_crt.c
+++ b/library/x509_crt.c
@@ -940,7 +940,7 @@
     WCHAR szDir[MAX_PATH];
     char filename[MAX_PATH];
 	char *p;
-    int len = strlen( path );
+    int len = (int) strlen( path );
 
 	WIN32_FIND_DATAW file_data;
     HANDLE hFind;