diff --git a/gebs.c b/gebs.c
index 765fb4b..cbd8edb 100644
--- a/gebs.c
+++ b/gebs.c
@@ -9,10 +9,14 @@ int main(int argc, char ** argv)
         gebs_mkdir("build");
     }
 
-    if (GEBS_CMD("gcc", "-ggdb", "-o", "build/self_rebuild", "example/self_rebuild.c") != 0)
-        return 1;
-    if (GEBS_CMD("gcc", "-ggdb", "-o", "build/arena", "example/arena.c") != 0)
-        return 1;
+    if (gebs_needs_rebuild_many("build/self_rebuild", "example/self_rebuild.c")) {
+        if (GEBS_CMD("gcc", "-ggdb", "-o", "build/self_rebuild", "example/self_rebuild.c") != 0)
+            return 1;
+    }
+    if (gebs_needs_rebuild_many("build/arena", "example/arena.c")) {
+        if (GEBS_CMD("gcc", "-ggdb", "-o", "build/arena", "example/arena.c") != 0)
+            return 1;
+    }
 
     return 0;
 }
diff --git a/gebs.h b/gebs.h
index ec1bf91..7383294 100644
--- a/gebs.h
+++ b/gebs.h
@@ -236,6 +236,16 @@ void gebs_rebuild_self1_alloc(Gebs_Allocator *alloc, int argc, char ** argv,
                 sizeof(__argv)/sizeof(__argv[0]), (char**)__argv, __FILE__); \
     } while(0)
 
+#define gebs_needs_rebuild_many(out, ...) \
+({ \
+    const char *__deps[] = { __VA_ARGS__ }; \
+    bool __ok = true; \
+    for (size_t __i = 0; __i < sizeof(__deps)/sizeof(__deps[0]); __i++) { \
+        __ok = __ok && gebs_needs_rebuild((out), __deps[__i]); \
+    } \
+    __ok; \
+})
+
 // ----------------------------------------------------------------------------
 // Scratch arena
 // ----------------------------------------------------------------------------