diff --git a/profiles/features/prefix/standalone/kernel-2.6.16+/make.defaults b/profiles/features/prefix/standalone/kernel-2.6.16+/make.defaults
index 4f60922264474..b98ce4ffc95f4 100644
--- a/profiles/features/prefix/standalone/kernel-2.6.16+/make.defaults
+++ b/profiles/features/prefix/standalone/kernel-2.6.16+/make.defaults
@@ -13,10 +13,10 @@
 # utimensat is missing or not reliable until linux-2.6.32.
 # needed by python-3.
 # lutimes requires utimensat
-ac_cv_func_utimensat=no
-ac_cv_func_lutimes=no
+ac_cv_func_utimensat="no"
+ac_cv_func_lutimes="no"
 # pipe2 and dup3 requires >=linux-2.6.27.  Needed by python-3.
-ac_cv_func_pipe2=no
-ac_cv_func_dup3=no
+ac_cv_func_pipe2="no"
+ac_cv_func_dup3="no"
 # epoll_create1 requires >=linux-2.6.27.
-ac_cv_func_epoll_create1=no
+ac_cv_func_epoll_create1="no"
diff --git a/profiles/features/prefix/standalone/kernel-2.6.32+/make.defaults b/profiles/features/prefix/standalone/kernel-2.6.32+/make.defaults
index 056f07700a5d4..33e139f1ded29 100644
--- a/profiles/features/prefix/standalone/kernel-2.6.32+/make.defaults
+++ b/profiles/features/prefix/standalone/kernel-2.6.32+/make.defaults
@@ -1,4 +1,4 @@
 # This profile is supporting >=linux-2.6.32[a] and <linux-3.2[b].
 
 # only available in glibc-2.26.
-ac_cv_func_reallocarray=no
+ac_cv_func_reallocarray="no"
diff --git a/profiles/features/prefix/standalone/make.defaults b/profiles/features/prefix/standalone/make.defaults
index 09b32b13eaaa0..a5acafc188fa7 100644
--- a/profiles/features/prefix/standalone/make.defaults
+++ b/profiles/features/prefix/standalone/make.defaults
@@ -4,6 +4,6 @@
 # remove when python-3.4 goes end-of-life on 2019-03-16,
 # and when python-2.7 goes end-of-life on 2020-01-01.
 # https://docs.python.org/devguide/#status-of-python-branches
-ac_cv_func_getentropy=no
+ac_cv_func_getentropy="no"
 # Reconsider the stability of Prefix in 2019.
 ACCEPT_KEYWORDS="~${ARCH}"