diff --git a/str.c b/str.c
index 496760ab..b572c2d4 100644
--- a/str.c
+++ b/str.c
@@ -17,6 +17,8 @@
  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  */
 
+#include <stdio.h>
+#include <string.h>
 #include <ctype.h>
 #include "str.h"
 
@@ -42,3 +44,11 @@ int strcase_startswith(char *str, const char *substring, char **afterp)
   return 1;
 }
 
+/* Like strstr() but doesn't depend on null termination */
+const char *str_str(const char *s1,const char *s2,int s1len)
+{
+  int s2len=strlen(s2);
+  for(;*s1&&(s1len--);s1++)
+    if (!strncmp(s2,s1,s2len)) return s1;
+  return NULL;
+}
diff --git a/str.h b/str.h
index 7b792700..ee1c3f4d 100644
--- a/str.h
+++ b/str.h
@@ -37,5 +37,8 @@ int str_startswith(char *str, const char *substring, char **afterp);
  */
 int strcase_startswith(char *str, const char *substring, char **afterp);
 
+/* like strstr(), but doesn't depend on null termination.
+   @author Paul Gardner-Stephen <paul@servalproject.org> */
+const char *str_str(const char *s1,const char *s2,int s1len);
 
-#endif
\ No newline at end of file
+#endif