diff --git a/cmake/Install.cmake b/cmake/Install.cmake
index 256e67360..0f6570c89 100644
--- a/cmake/Install.cmake
+++ b/cmake/Install.cmake
@@ -113,13 +113,13 @@ INSTALL(FILES share/config.fish
 # -$v $(INSTALL) -m 755 -d $(DESTDIR)$(extra_completionsdir)
 # -$v $(INSTALL) -m 755 -d $(DESTDIR)$(extra_functionsdir)
 # -$v $(INSTALL) -m 755 -d $(DESTDIR)$(extra_confdir)
-# Don't try too hard to create these directories as they may be outside our writeable area
-# https://github.com/Homebrew/homebrew-core/pull/2813
-FISH_TRY_CREATE_DIRS(${rel_datadir}/pkgconfig)
-FISH_TRY_CREATE_DIRS(${extra_completionsdir} ${extra_functionsdir} ${extra_confdir})
+# Create only the vendor directories inside the prefix (#5029 / #6508)
+FISH_CREATE_DIRS(${rel_datadir}/fish/vendor_completions.d ${rel_datadir}/fish/vendor_functions.d
+    ${rel_datadir}/fish/vendor_conf.d)
 
 # @echo "Installing pkgconfig file"
 # $v $(INSTALL) -m 644 fish.pc $(DESTDIR)$(datadir)/pkgconfig
+FISH_TRY_CREATE_DIRS(${rel_datadir}/pkgconfig)
 CONFIGURE_FILE(fish.pc.in fish.pc.noversion)
 
 ADD_CUSTOM_COMMAND(OUTPUT fish.pc