diff --git a/src/core/collector.ml b/src/core/collector.ml
index ee280b3..26d1257 100644
--- a/src/core/collector.ml
+++ b/src/core/collector.ml
@@ -9,9 +9,6 @@ open Types
 
 let dummy_span : span = Int64.min_int
 
-let dummy_explicit_span : explicit_span =
-  { span = dummy_span; meta = Meta_map.empty }
-
 (** Signature for a collector.
 
     This is only relevant to implementors of tracing backends; to instrument
diff --git a/src/core/types.ml b/src/core/types.ml
index 9472385..40257a4 100644
--- a/src/core/types.ml
+++ b/src/core/types.ml
@@ -12,11 +12,3 @@ type user_data =
   ]
 (** User defined data, generally passed as key/value pairs to
     whatever collector is installed (if any). *)
-
-type explicit_span = {
-  span: span;
-      (** Identifier for this span. Several explicit spans might share the same
-      identifier since we can differentiate between them via [meta]. *)
-  mutable meta: Meta_map.t;  (** Metadata for this span (and its context) *)
-}
-(** Explicit span, with collector-specific metadata *)