-diff --git a/ccache.c b/ccache.c
-index 88e0ec5..7dffeb4 100644
---- a/ccache.c
-+++ b/ccache.c
-@@ -1762,6 +1762,7 @@ calculate_object_hash(struct args *args, struct mdfour *hash, int direct_mode)
- "CPLUS_INCLUDE_PATH",
- "OBJC_INCLUDE_PATH",
- "OBJCPLUS_INCLUDE_PATH", // clang
-+ "GCC_HONOUR_COPTS",
- NULL
- };
- for (const char **p = envvars; *p; ++p) {
+--- a/src/ccache.cpp
++++ b/src/ccache.cpp
+@@ -1841,6 +1841,7 @@ get_manifest_key(Context& ctx, Hash& has
+ "OBJCPLUS_INCLUDE_PATH", // Clang
+ "CLANG_CONFIG_FILE_SYSTEM_DIR", // Clang
+ "CLANG_CONFIG_FILE_USER_DIR", // Clang
++ "GCC_HONOUR_COPTS",
+ nullptr,
+ };
+ for (const char** p = envvars; *p; ++p) {