1 files changed, 6 insertions, 3 deletions
diff --git a/st.c b/st.c
index 12e45c27de..e778b69c5a 100644
--- a/st.c
+++ b/st.c
@@ -7,6 +7,7 @@
 #include "st.h"
 #else
 #include "ruby/ruby.h"
+#include "internal.h"
 #endif
 
 #include <stdio.h>
@@ -30,7 +31,9 @@ typedef struct st_packed_entry {
     st_data_t key, val;
 } st_packed_entry;
 
-#define STATIC_ASSERT(name, expr) typedef int static_assert_##name##_check[(expr) ? 1 : -1];
+#ifndef STATIC_ASSERT
+#define STATIC_ASSERT(name, expr) typedef int static_assert_##name##_check[(expr) ? 1 : -1]
+#endif
 
 #define ST_DEFAULT_MAX_DENSITY 5
 #define ST_DEFAULT_INIT_TABLE_SIZE 16
@@ -38,8 +41,8 @@ typedef struct st_packed_entry {
 #define PACKED_UNIT (int)(sizeof(st_packed_entry) / sizeof(st_table_entry*))
 #define MAX_PACKED_HASH (int)(ST_DEFAULT_PACKED_TABLE_SIZE * sizeof(st_table_entry*) / sizeof(st_packed_entry))
 
-STATIC_ASSERT(st_packed_entry, sizeof(st_packed_entry) == sizeof(st_table_entry*[PACKED_UNIT]))
-STATIC_ASSERT(st_packed_bins, sizeof(st_packed_entry[MAX_PACKED_HASH]) <= sizeof(st_table_entry*[ST_DEFAULT_PACKED_TABLE_SIZE]))
+STATIC_ASSERT(st_packed_entry, sizeof(st_packed_entry) == sizeof(st_table_entry*[PACKED_UNIT]));
+STATIC_ASSERT(st_packed_bins, sizeof(st_packed_entry[MAX_PACKED_HASH]) <= sizeof(st_table_entry*[ST_DEFAULT_PACKED_TABLE_SIZE]));
 
     /*
      * DEFAULT_MAX_DENSITY is the default for the largest we allow the