diff --git a/tests/functional2/lang/nul_bytes_parsers/eval-allow-depr-fromJSON-key.out.exp b/tests/functional2/lang/nul_bytes_parsers/eval-allow-depr-fromJSON-key.out.exp
new file mode 100644
index 000000000..88878fa0a
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diff --git a/tests/functional2/lang/nul_bytes_parsers/eval-allow-depr-fromJSON-value.out.exp b/tests/functional2/lang/nul_bytes_parsers/eval-allow-depr-fromJSON-value.out.exp
new file mode 100644
index 000000000..231f150c5
--- /dev/null
+++ b/tests/functional2/lang/nul_bytes_parsers/eval-allow-depr-fromJSON-value.out.exp
@@ -0,0 +1 @@
+"a"
diff --git a/tests/functional2/lang/nul_bytes_parsers/eval-allow-depr-fromTOML-key.out.exp b/tests/functional2/lang/nul_bytes_parsers/eval-allow-depr-fromTOML-key.out.exp
new file mode 100644
index 000000000..88878fa0a
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diff --git a/tests/functional2/lang/nul_bytes_parsers/eval-allow-depr-fromTOML-value.out.exp b/tests/functional2/lang/nul_bytes_parsers/eval-allow-depr-fromTOML-value.out.exp
new file mode 100644
index 000000000..01cdaa278
--- /dev/null
+++ b/tests/functional2/lang/nul_bytes_parsers/eval-allow-depr-fromTOML-value.out.exp
@@ -0,0 +1 @@
+{ k = "a"; }
diff --git a/tests/functional2/lang/nul_bytes_parsers/eval-depr-fromJSON-key.out.exp b/tests/functional2/lang/nul_bytes_parsers/eval-depr-fromJSON-key.out.exp
new file mode 100644
index 000000000..88878fa0a
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diff --git a/tests/functional2/lang/nul_bytes_parsers/eval-depr-fromJSON-value.out.exp b/tests/functional2/lang/nul_bytes_parsers/eval-depr-fromJSON-value.out.exp
new file mode 100644
index 000000000..231f150c5
--- /dev/null
+++ b/tests/functional2/lang/nul_bytes_parsers/eval-depr-fromJSON-value.out.exp
@@ -0,0 +1 @@
+"a"
diff --git a/tests/functional2/lang/nul_bytes_parsers/eval-depr-fromTOML-key.out.exp b/tests/functional2/lang/nul_bytes_parsers/eval-depr-fromTOML-key.out.exp
new file mode 100644
index 000000000..88878fa0a
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diff --git a/tests/functional2/lang/nul_bytes_parsers/eval-depr-fromTOML-value.out.exp b/tests/functional2/lang/nul_bytes_parsers/eval-depr-fromTOML-value.out.exp
new file mode 100644
index 000000000..01cdaa278
--- /dev/null
+++ b/tests/functional2/lang/nul_bytes_parsers/eval-depr-fromTOML-value.out.exp
@@ -0,0 +1 @@
+{ k = "a"; }
diff --git a/tests/functional2/lang/nul_bytes_parsers/in-fromJSON-key.nix b/tests/functional2/lang/nul_bytes_parsers/in-fromJSON-key.nix
new file mode 100644
index 000000000..ffaa6a97d
--- /dev/null
+++ b/tests/functional2/lang/nul_bytes_parsers/in-fromJSON-key.nix
@@ -0,0 +1 @@
+builtins.fromJSON ''{"a\u0000b": 1}''
diff --git a/tests/functional2/lang/nul_bytes_parsers/in-fromJSON-value.nix b/tests/functional2/lang/nul_bytes_parsers/in-fromJSON-value.nix
new file mode 100644
index 000000000..c71ab990d
--- /dev/null
+++ b/tests/functional2/lang/nul_bytes_parsers/in-fromJSON-value.nix
@@ -0,0 +1 @@
+builtins.fromJSON ''"a\u0000b"''
diff --git a/tests/functional2/lang/nul_bytes_parsers/in-fromTOML-key.nix b/tests/functional2/lang/nul_bytes_parsers/in-fromTOML-key.nix
new file mode 100644
index 000000000..b622dc4dc
--- /dev/null
+++ b/tests/functional2/lang/nul_bytes_parsers/in-fromTOML-key.nix
@@ -0,0 +1 @@
+builtins.fromTOML ''"a\u0000b" = 1''
diff --git a/tests/functional2/lang/nul_bytes_parsers/in-fromTOML-value.nix b/tests/functional2/lang/nul_bytes_parsers/in-fromTOML-value.nix
new file mode 100644
index 000000000..183cab6b3
--- /dev/null
+++ b/tests/functional2/lang/nul_bytes_parsers/in-fromTOML-value.nix
@@ -0,0 +1 @@
+builtins.fromTOML ''k = "a\u0000b"''
diff --git a/tests/functional2/lang/nul_bytes_parsers/test.toml b/tests/functional2/lang/nul_bytes_parsers/test.toml
new file mode 100644
index 000000000..14dabfd4e
--- /dev/null
+++ b/tests/functional2/lang/nul_bytes_parsers/test.toml
@@ -0,0 +1,11 @@
+[[test]]
+name = "eval-depr"
+matrix = true
+# FIXME: These should fail.
+runner = "eval-okay"
+
+[[test]]
+name = "eval-allow-depr"
+matrix = true
+runner = "eval-okay"
+flags = ["--extra-deprecated-features", "nul-bytes"]