diff --git a/dev-util/cmake/cmake-3.22.3.ebuild b/dev-util/cmake/cmake-3.22.3.ebuild
index b8ec458aff012..0d8e28da59fd8 100644
--- a/dev-util/cmake/cmake-3.22.3.ebuild
+++ b/dev-util/cmake/cmake-3.22.3.ebuild
@@ -5,7 +5,8 @@ EAPI=8
 
 # TODO RunCMake.LinkWhatYouUse fails consistently w/ ninja
 # ... but seems fine as of 3.22.3?
-#CMAKE_MAKEFILE_GENERATOR="emake"
+# TODO ... but bootstrap sometimes(?) fails with ninja now. bug #834759.
+CMAKE_MAKEFILE_GENERATOR="emake"
 CMAKE_REMOVE_MODULES_LIST=( none )
 inherit bash-completion-r1 cmake elisp-common flag-o-matic multiprocessing \
 	toolchain-funcs virtualx xdg-utils
diff --git a/dev-util/cmake/cmake-3.23.0_rc2.ebuild b/dev-util/cmake/cmake-3.23.0_rc2.ebuild
index 3ea3a971a1e86..96c6c3f0cae68 100644
--- a/dev-util/cmake/cmake-3.23.0_rc2.ebuild
+++ b/dev-util/cmake/cmake-3.23.0_rc2.ebuild
@@ -5,7 +5,8 @@ EAPI=8
 
 # TODO RunCMake.LinkWhatYouUse fails consistently w/ ninja
 # ... but seems fine as of 3.22.3?
-#CMAKE_MAKEFILE_GENERATOR="emake"
+# TODO ... but bootstrap sometimes(?) fails with ninja now. bug #834759.
+CMAKE_MAKEFILE_GENERATOR="emake"
 CMAKE_REMOVE_MODULES_LIST=( none )
 inherit bash-completion-r1 cmake elisp-common flag-o-matic multiprocessing \
 	toolchain-funcs virtualx xdg-utils
diff --git a/dev-util/cmake/cmake-9999.ebuild b/dev-util/cmake/cmake-9999.ebuild
index 8dcd760224547..402d531d597dd 100644
--- a/dev-util/cmake/cmake-9999.ebuild
+++ b/dev-util/cmake/cmake-9999.ebuild
@@ -5,7 +5,8 @@ EAPI=8
 
 # TODO RunCMake.LinkWhatYouUse fails consistently w/ ninja
 # ... but seems fine as of 3.22.3?
-#CMAKE_MAKEFILE_GENERATOR="emake"
+# TODO ... but bootstrap sometimes(?) fails with ninja now. bug #834759.
+CMAKE_MAKEFILE_GENERATOR="emake"
 CMAKE_REMOVE_MODULES_LIST=( none )
 inherit bash-completion-r1 cmake elisp-common flag-o-matic multiprocessing \
 	toolchain-funcs virtualx xdg-utils