1 files changed, 2 insertions, 0 deletions
diff --git a/malloc.c b/malloc.c
index 5d9652e869..42c2d651c6 100644
--- a/malloc.c
+++ b/malloc.c
@@ -894,9 +894,11 @@ Malloc_t Perl_sbrk (int size);
 #include <unistd.h>
 #endif
 #else
+#ifndef HAS_SBRK_PROTO
 extern	Malloc_t sbrk(int);
 #endif
 #endif
+#endif
 
 #ifdef DEBUGGING_MSTATS
 /*