diff --git a/TODOS.md b/TODOS.md
index e5edb13..68dd36d 100644
--- a/TODOS.md
+++ b/TODOS.md
@@ -2,6 +2,7 @@
 
 - Polish existing features before moving on to new ones.
 - [ ] Improve diagnostics
+  - [ ] keep track of every error and don't report them more than once.
   - [ ] All Diagnostics should show:
     - [ ] *What* went wrong
     - [ ] *where* (in the file)
diff --git a/menus.odin b/menus.odin
index 4b19eea..d102795 100644
--- a/menus.odin
+++ b/menus.odin
@@ -393,4 +393,3 @@ parse_config_menus :: proc(
 
 	return result
 }
-
diff --git a/mustache/diagnostic.odin b/mustache/diagnostic.odin
index 59a7c82..43e629d 100644
--- a/mustache/diagnostic.odin
+++ b/mustache/diagnostic.odin
@@ -309,14 +309,18 @@ write_gutter :: proc(sb: ^strings.Builder, width: int, faint: string, reset: str
 
 // format_render_error produces a diagnostic for an Error value using the
 // template's path and source for context. Returns "" for nil errors.
+// If the error carries its own source/path (from tag_error), those are used
+// instead of the passed-in template — this ensures errors inside partials
+// point at the correct file.
 format_render_error :: proc(err: Error, tmpl: Template, colorize: bool = false) -> string {
 	if err == nil {
 		return ""
 	}
-	path := tmpl.path
+	b := body(err)
+	source := b.source != "" ? b.source : tmpl.source
+	path := b.path != "" ? b.path : tmpl.path
 	if path == "" {
 		path = "<input>"
 	}
-	b := body(err)
-	return format_error(path, tmpl.source, b.pos, b.msg, colorize = colorize)
+	return format_error(path, source, b.pos, b.msg, colorize = colorize)
 }
diff --git a/mustache/mustache.odin b/mustache/mustache.odin
index 9165872..bf3783a 100644
--- a/mustache/mustache.odin
+++ b/mustache/mustache.odin
@@ -26,9 +26,11 @@ Error_Kind :: enum {
 }
 
 Error_Body :: struct {
-	msg:  string,
-	pos:  int,
-	kind: Error_Kind,
+	msg:    string,
+	pos:    int,
+	kind:   Error_Kind,
+	source: string,
+	path:   string,
 }
 
 // Error is nil when no error occurred.
@@ -47,6 +49,20 @@ body :: proc(err: Error) -> Error_Body {
 	}
 }
 
+// tag_error stamps an Error with the source/path of the template where it
+// originated, so diagnostics point at the correct file (e.g. a partial).
+tag_error :: proc(err: Error, tmpl: Template) -> Error {
+	if err == nil do return nil
+	b := body(err)
+	return Error_Body {
+		msg = b.msg,
+		pos = b.pos,
+		kind = b.kind,
+		source = tmpl.source,
+		path = tmpl.path,
+	}
+}
+
 // ---------------------------------------------------------------------------
 // Node tree
 // ---------------------------------------------------------------------------
@@ -585,7 +601,7 @@ render_nodes :: proc(
 			if len(node.filters) > 0 {
 				transformed, perr := apply_pipeline(val, node.filters[:], node.pos, ctx[:])
 				if perr != nil {
-					return perr
+					return tag_error(perr, current)
 				}
 				val = transformed
 			}
@@ -627,7 +643,7 @@ render_nodes :: proc(
 			if len(node.filters) > 0 {
 				transformed, perr := apply_pipeline(val, node.filters[:], node.pos, ctx[:])
 				if perr != nil {
-					return perr
+					return tag_error(perr, current)
 				}
 				val = transformed
 			}
@@ -665,7 +681,7 @@ render_nodes :: proc(
 			if len(node.filters) > 0 {
 				transformed, perr := apply_pipeline(val, node.filters[:], node.pos, ctx[:])
 				if perr != nil {
-					return perr
+					return tag_error(perr, current)
 				}
 				val = transformed
 			}
@@ -729,7 +745,7 @@ render_nodes :: proc(
 			if len(node.filters) > 0 {
 				transformed, perr := apply_pipeline(val, node.filters[:], node.pos, ctx[:])
 				if perr != nil {
-					return perr
+					return tag_error(perr, current)
 				}
 				val = transformed
 			}