diff --git a/mpdpopm/Cargo.toml.in b/mpdpopm/Cargo.toml.in
index ea528b5..5d5bc2a 100644
--- a/mpdpopm/Cargo.toml.in
+++ b/mpdpopm/Cargo.toml.in
@@ -35,8 +35,10 @@ os_str_bytes = "2.3.1"
 pin-project = "1.0.8"
 regex = "1.3.6"
 serde = { version = "1.0", features = ["derive"] }
+serde_spanned = "=0.6.3" # Pin to preserve the ability to build with rust 1.65
 serde-lexpr = "0.1.1"
 toml = "=0.7.6" # Pin to preserve the ability to build with rust 1.65
+toml_datetime = "=0.6.3" # Pin to preserve the ability to build with rust 1.65
 toml_edit = "=0.19.12" # Pin to preserve the ability to build with rust 1.65
 tokio = { version = "1.15.0", features = ["io-util", "macros", "net", "process", "rt-multi-thread", "signal", "time"] }