diff --git a/src/include/ngspice/ngspice.h b/src/include/ngspice/ngspice.h
index 801d70953..aafff44b6 100644
--- a/src/include/ngspice/ngspice.h
+++ b/src/include/ngspice/ngspice.h
@@ -218,6 +218,13 @@ extern double x_atanh(double);
 #endif
 #endif
 
+#ifndef EXT_ASC
+#if defined(__MINGW__) || defined(_MSC_VER)
+#define fopen newfopen
+extern FILE *newfopen(char *fn, char* md);
+#endif
+#endif
+
 #if defined(__GNUC__)
 #define ATTRIBUTE_NORETURN __attribute__ ((noreturn))
 #elif defined(_MSC_VER)