diff --git a/src/core/span.ml b/src/core/span.ml
index 0e3d1750..787c11a7 100644
--- a/src/core/span.ml
+++ b/src/core/span.ml
@@ -144,4 +144,4 @@ let set_status = span_set_status
 
 let set_kind = span_set_kind
 
-let k_context : t Context.key = Context.new_key ()
+let k_ambient : t Context.key = Context.new_key ()
diff --git a/src/core/span.mli b/src/core/span.mli
index 793b8ce1..e3160930 100644
--- a/src/core/span.mli
+++ b/src/core/span.mli
@@ -124,4 +124,6 @@ val default_kind : Span_kind.t ref
     set to "internal", following directions from the [.proto] file. It can be
     convenient to set "client" or "server" uniformly in here. *)
 
-val k_context : t Context.key
+val k_ambient : t Context.key
+(** Context key to carry around a {!Span.t} in ambient context.
+    @since NEXT_RELEASE *)
diff --git a/src/core/span_ctx.ml b/src/core/span_ctx.ml
index 1be170f2..5b72755b 100644
--- a/src/core/span_ctx.ml
+++ b/src/core/span_ctx.ml
@@ -88,4 +88,4 @@ let of_w3c_trace_context_exn bs =
   | Ok t -> t
   | Error msg -> invalid_arg @@ spf "invalid w3c trace context: %s" msg
 
-let k_span_ctx : t Hmap.key = Hmap.Key.create ()
+let k_ambient : t Hmap.key = Hmap.Key.create ()
diff --git a/src/core/span_ctx.mli b/src/core/span_ctx.mli
index fb72046b..2970daab 100644
--- a/src/core/span_ctx.mli
+++ b/src/core/span_ctx.mli
@@ -36,7 +36,7 @@ val of_w3c_trace_context : bytes -> (t, string) result
 val of_w3c_trace_context_exn : bytes -> t
 (** @raise Invalid_argument if parsing failed *)
 
-val k_span_ctx : t Hmap.key
+val k_ambient : t Hmap.key
 (** Hmap key to carry around a {!Span_ctx.t}, e.g. to remember what the current
     parent span is.
     @since 0.8 *)
diff --git a/src/lib/ambient_span.ml b/src/lib/ambient_span.ml
index b8cc84e6..41d20edd 100644
--- a/src/lib/ambient_span.ml
+++ b/src/lib/ambient_span.ml
@@ -1,9 +1,9 @@
 (** Find current span from ambient-context *)
 let[@inline] get () : Span.t option =
-  Opentelemetry_ambient_context.get Span.k_context
+  Opentelemetry_ambient_context.get Span.k_ambient
 
 (** [with_ambient span f] runs [f()] with the current ambient span being set to
     [span] *)
 let[@inline] with_ambient (span : Span.t) (f : unit -> 'a) : 'a =
-  Opentelemetry_ambient_context.with_key_bound_to Span.k_context span (fun _ ->
+  Opentelemetry_ambient_context.with_key_bound_to Span.k_ambient span (fun _ ->
       f ())
diff --git a/src/lib/opentelemetry.ml b/src/lib/opentelemetry.ml
index 15284f32..25d4ddac 100644
--- a/src/lib/opentelemetry.ml
+++ b/src/lib/opentelemetry.ml
@@ -40,7 +40,7 @@ let k_trace_id = Trace_id.k_trace_id
 module Span_id = Span_id
 module Span_ctx = Span_ctx
 
-let k_span_ctx = Span_ctx.k_span_ctx
+let k_ambient = Span_ctx.k_ambient
 
 (** {2 Attributes and conventions} *)
 
diff --git a/src/trace/opentelemetry_trace.ml b/src/trace/opentelemetry_trace.ml
index 95e439ad..248c8caa 100644
--- a/src/trace/opentelemetry_trace.ml
+++ b/src/trace/opentelemetry_trace.ml
@@ -36,9 +36,9 @@ open struct
   (* sanity check: otrace meta-map must be the same as hmap *)
   let () = ignore (fun (k : _ Hmap.key) : _ Ambient_context.Context.key -> k)
 
-  (** Key to access the current span context. *)
+  (** Key to access the current span context. Uses the shared key from core. *)
   let k_span_ctx : OTEL.Span_ctx.t Ambient_context.Context.key =
-    Ambient_context.Context.new_key ()
+    OTEL.Span_ctx.k_ambient
 
   let enter_span (self : state) ~__FUNCTION__ ~__FILE__ ~__LINE__ ~level:_
       ~params:_ ~(data : (_ * Otrace.user_data) list) ~parent name : Otrace.span