diff --git a/lib/isc/include/isc/util.h b/lib/isc/include/isc/util.h
index 97eb51a193..ecd9e8c52a 100644
--- a/lib/isc/include/isc/util.h
+++ b/lib/isc/include/isc/util.h
@@ -208,6 +208,18 @@
 #define ISC_UNREACHABLE()
 #endif
 
+#if !defined(__has_feature)
+#define __has_feature(x) 0
+#endif
+
+#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR >= 6)
+#define STATIC_ASSERT(cond, msg) _Static_assert(cond, msg)
+#elif __has_feature(c_static_assert)
+#define STATIC_ASSERT(cond, msg) _Static_assert(cond, msg)
+#else
+#define STATIC_ASSERT(cond, msg) INSIST(cond)
+#endif
+
 #ifdef UNIT_TESTING
 extern void mock_assert(const int result, const char* const expression,
 			const char * const file, const int line);
diff --git a/lib/isc/mem.c b/lib/isc/mem.c
index 0b72e41e8d..7a2691f481 100644
--- a/lib/isc/mem.c
+++ b/lib/isc/mem.c
@@ -747,7 +747,8 @@ isc_mem_createx(size_t init_max_size, size_t target_size,
 	REQUIRE(memalloc != NULL);
 	REQUIRE(memfree != NULL);
 
-	INSIST((ALIGNMENT_SIZE & (ALIGNMENT_SIZE - 1)) == 0);
+	STATIC_ASSERT((ALIGNMENT_SIZE & (ALIGNMENT_SIZE - 1)) == 0,
+		      "wrong alignment size");
 
 	RUNTIME_CHECK(isc_once_do(&once, initialize_action) == ISC_R_SUCCESS);