strcasecmp is in <strings.h>
diff --git a/src/common.h b/src/common.h
index 9c8bdc1..dd97a30 100644
--- a/src/common.h
+++ b/src/common.h
@@ -44,6 +44,7 @@
#else
# include <unistd.h>
+# include <strings.h>
# ifdef GIT_THREADS
# include <pthread.h>
# include <sched.h>