diff --git a/apache2/msc_util.c b/apache2/msc_util.c
index a3ecc701..b82270c3 100644
--- a/apache2/msc_util.c
+++ b/apache2/msc_util.c
@@ -570,7 +570,7 @@ char *file_basename(apr_pool_t *mp, const char *filename) {
     return d;
 }
 
-#ifdef WIN32
+#if defined(WIN32) || !defined(HAVE_STRCASESTR)
 char *strcasestr(const char *haystack, const char *needle) {
     char aux, lower_aux;
     int length;
@@ -588,7 +588,8 @@ char *strcasestr(const char *haystack, const char *needle) {
     }
     return ((char *)haystack);
 }
-
+#endif
+#ifdef WIN32
 int inet_pton(int family, const char *src, void *dst)   {
     struct addrinfo addr;
     struct sockaddr_in *in = NULL;
diff --git a/apache2/msc_util.h b/apache2/msc_util.h
index 80c8cadf..a337a65f 100644
--- a/apache2/msc_util.h
+++ b/apache2/msc_util.h
@@ -31,6 +31,8 @@
 #ifdef WIN32
 #include <ws2tcpip.h>
 int DSOLOCAL inet_pton(int family, const char *src, void *dst);
+#endif
+#if defined(WIN32) || !defined(HAVE_STRCASESTR)
 char DSOLOCAL *strcasestr(const char *haystack, const char *needle);
 #endif
 
diff --git a/configure.ac b/configure.ac
index 681d3790..4abfdb2e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -46,7 +46,7 @@ AC_TYPE_UINT8_T
 # Checks for library functions.
 AC_FUNC_MALLOC
 AC_FUNC_MEMCMP
-AC_CHECK_FUNCS([atexit getcwd memmove memset strcasecmp strchr strdup strerror strncasecmp strrchr strstr strtol fchmod])
+AC_CHECK_FUNCS([atexit getcwd memmove memset strcasecmp strchr strdup strerror strncasecmp strrchr strstr strtol fchmod strcasestr])
 
 # Some directories
 MSC_BASE_DIR=`pwd`