diff --git a/test/standalone/config_header/autoconf_at/autoconf_at.txt b/test/standalone/config_header/autoconf_at/autoconf_at.txt
new file mode 100644
index 0000000000000000000000000000000000000000..fccd1255f887c410c0f86a87d51e531685a4382b
--- /dev/null
+++ b/test/standalone/config_header/autoconf_at/autoconf_at.txt
@@ -0,0 +1,37 @@
+/* This file was generated by ConfigHeader using the Zig Build System. */
+// empty strings are preserved
+
+// line with misc content is preserved
+no substitution
+// empty @ sigils are preserved
+@
+@@
+@@@
+@@@@
+// simple substitution
+
+
+1
+0
+42
+text
+// double packed substitution
+texttext
+// triple packed substitution
+text42text
+// double separated substitution
+42.42
+// triple separated substitution
+42.1.42
+// misc prefix is preserved
+false is 0
+// misc suffix is preserved
+1 is true
+// surrounding content is preserved
+what is 6*7? 42!
+// incomplete key is preserved
+@undefined
+// @-vars resolved only when they wrap valid characters, otherwise considered literals
+@text@
+// expanded variables are considered strings after expansion
+@string@
diff --git a/test/standalone/config_header/autoconf_at/autoconf_at.txt.in b/test/standalone/config_header/autoconf_at/autoconf_at.txt.in
new file mode 100644
index 0000000000000000000000000000000000000000..8dfbab96d7b4483305352787cc32e420f606f0db
--- /dev/null
+++ b/test/standalone/config_header/autoconf_at/autoconf_at.txt.in
@@ -0,0 +1,36 @@
+// empty strings are preserved
+
+// line with misc content is preserved
+no substitution
+// empty @ sigils are preserved
+@
+@@
+@@@
+@@@@
+// simple substitution
+@undefined@
+@defined@
+@boolean_true@
+@boolean_false@
+@integer@
+@string@
+// double packed substitution
+@string@@string@
+// triple packed substitution
+@string@@integer@@string@
+// double separated substitution
+@integer@.@integer@
+// triple separated substitution
+@integer@.@boolean_true@.@integer@
+// misc prefix is preserved
+false is @boolean_false@
+// misc suffix is preserved
+@boolean_true@ is true
+// surrounding content is preserved
+what is 6*7? @integer@!
+// incomplete key is preserved
+@undefined
+// @-vars resolved only when they wrap valid characters, otherwise considered literals
+@@string@@
+// expanded variables are considered strings after expansion
+@string_at@