diff --git a/acconfig.h b/acconfig.h
index cfdf3fc..4911dbe 100644
--- a/acconfig.h
+++ b/acconfig.h
@@ -97,5 +97,8 @@
 /* Define this to something sane if you don't have stricmp */
 #undef stricmp
 
+/* Define this if fnmatch is prototyped in fnmatch.h */
+#undef HAVE_FNMATCH_PROTO
+
 @BOTTOM@
 #endif // _CONFIG_H
diff --git a/configure.in b/configure.in
index d8be30c..c3c5392 100644
--- a/configure.in
+++ b/configure.in
@@ -80,6 +80,15 @@ AC_HEADER_TIME
 AC_STRUCT_TM
 AC_C_BIGENDIAN
 
+AC_MSG_CHECKING(that fnmatch is in fnmatch.h)
+AC_TRY_COMPILE(
+	[#include <fnmatch.h>],
+	[int (*foo)() = fnmatch;],
+	AC_DEFINE(HAVE_FNMATCH_PROTO)
+	AC_MSG_RESULT(yes),
+	AC_MSG_RESULT(no)
+)
+
 AC_MSG_CHECKING(for socklen_t in sys/types.h)
 AC_TRY_COMPILE(
 	[#include <sys/types.h>],
diff --git a/source/quakefs.c b/source/quakefs.c
index 5f1973f..a682e32 100644
--- a/source/quakefs.c
+++ b/source/quakefs.c
@@ -68,6 +68,10 @@
 #endif
 #include <limits.h>
 
+#ifndef HAVE_FNMATCH_PROTO
+fnmatch (__const char *__pattern, __const char *__string, int __flags);
+#endif
+
 
 extern qboolean      is_server;