diff --git a/Cargo.toml b/Cargo.toml
index 948a5769d..a97e6fc72 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -21,7 +21,7 @@ rustdoc-args = ["--cfg", "docsrs"]
 default = ["std"]
 std = ["alloc", "secp256k1-sys/std", "rand?/std", "rand?/std_rng", "rand?/thread_rng", "hashes?/std"]
 # allow use of Secp256k1::new and related API that requires an allocator
-alloc = ["secp256k1-sys/alloc"]
+alloc = ["secp256k1-sys/alloc", "hashes?/alloc"]
 recovery = ["secp256k1-sys/recovery"]
 lowmemory = ["secp256k1-sys/lowmemory"]
 global-context = ["std"]