diff --git a/libc/src/__support/libc_assert.h b/libc/src/__support/libc_assert.h
index ada1795ccb80a..6e0b5bd3d68b4 100644
--- a/libc/src/__support/libc_assert.h
+++ b/libc/src/__support/libc_assert.h
@@ -14,9 +14,11 @@
 // The build is configured to just use the public <assert.h> API
 // for libc's internal assertions.
 
+#ifndef LIBC_ASSERT
 #include <assert.h>
 
 #define LIBC_ASSERT(COND) assert(COND)
+#endif // LIBC_ASSERT
 
 #else // Not LIBC_COPT_USE_C_ASSERT