diff --git a/src/third_party/curl/curlbuild.h b/src/third_party/curl/curlbuild.h
index b0a53e6c..595df4e4 100644
--- a/src/third_party/curl/curlbuild.h
+++ b/src/third_party/curl/curlbuild.h
@@ -155,7 +155,8 @@
 
 /* The size of `long', as computed by sizeof. */
 #if defined(_M_X64) || (defined(__x86_64__) && !defined(__ILP32__)) ||      \
-    defined(__aarch64__) || (defined(__mips__) && _MIPS_SIM == _ABI64)
+    defined(__aarch64__) || (defined(__mips__) && _MIPS_SIM == _ABI64) ||   \
+    defined(__powerpc64__) || defined(__s390x__) || defined(__LP64__)
 #define CURL_SIZEOF_LONG 8
 #else
 #define CURL_SIZEOF_LONG 4