diff --git a/tfdiags/contextual.go b/tfdiags/contextual.go
index f66e5d913..c59280f34 100644
--- a/tfdiags/contextual.go
+++ b/tfdiags/contextual.go
@@ -19,17 +19,20 @@ import (
 
 // contextualFromConfig is an interface type implemented by diagnostic types
 // that can elaborate themselves when given information about the configuration
-// body they are embedded in.
+// body they are embedded in, as well as the runtime address associated with
+// that configuration.
 //
 // Usually this entails extracting source location information in order to
 // populate the "Subject" range.
 type contextualFromConfigBody interface {
-	ElaborateFromConfigBody(hcl.Body) Diagnostic
+	ElaborateFromConfigBody(hcl.Body, string) Diagnostic
 }
 
 // InConfigBody returns a copy of the receiver with any config-contextual
-// diagnostics elaborated in the context of the given body.
-func (diags Diagnostics) InConfigBody(body hcl.Body) Diagnostics {
+// diagnostics elaborated in the context of the given body. An optional address
+// argument may be added to indicate which instance of the configuration the
+// error related to.
+func (diags Diagnostics) InConfigBody(body hcl.Body, addr string) Diagnostics {
 	if len(diags) == 0 {
 		return nil
 	}
@@ -37,7 +40,7 @@ func (diags Diagnostics) InConfigBody(body hcl.Body) Diagnostics {
 	ret := make(Diagnostics, len(diags))
 	for i, srcDiag := range diags {
 		if cd, isCD := srcDiag.(contextualFromConfigBody); isCD {
-			ret[i] = cd.ElaborateFromConfigBody(body)
+			ret[i] = cd.ElaborateFromConfigBody(body, addr)
 		} else {
 			ret[i] = srcDiag
 		}
@@ -112,7 +115,12 @@ type attributeDiagnostic struct {
 // source location information is still available, for more accuracy. This
 // is not always possible due to system architecture, so this serves as a
 // "best effort" fallback behavior for such situations.
-func (d *attributeDiagnostic) ElaborateFromConfigBody(body hcl.Body) Diagnostic {
+func (d *attributeDiagnostic) ElaborateFromConfigBody(body hcl.Body, addr string) Diagnostic {
+	// don't change an existing address
+	if d.address == "" {
+		d.address = addr
+	}
+
 	if len(d.attrPath) < 1 {
 		// Should never happen, but we'll allow it rather than crashing.
 		return d
@@ -353,7 +361,12 @@ type wholeBodyDiagnostic struct {
 	subject *SourceRange // populated only after ElaborateFromConfigBody
 }
 
-func (d *wholeBodyDiagnostic) ElaborateFromConfigBody(body hcl.Body) Diagnostic {
+func (d *wholeBodyDiagnostic) ElaborateFromConfigBody(body hcl.Body, addr string) Diagnostic {
+	// don't change an existing address
+	if d.address == "" {
+		d.address = addr
+	}
+
 	if d.subject != nil {
 		// Don't modify an already-elaborated diagnostic.
 		return d
diff --git a/tfdiags/contextual_test.go b/tfdiags/contextual_test.go
index 806d0c3a9..e29712a7b 100644
--- a/tfdiags/contextual_test.go
+++ b/tfdiags/contextual_test.go
@@ -185,6 +185,7 @@ simple_attr = "val"
 				diagnosticBase: diagnosticBase{
 					summary: "preexisting",
 					detail:  "detail",
+					address: "original",
 				},
 				subject: &SourceRange{
 					Filename: "somewhere_else.tf",
@@ -535,9 +536,22 @@ simple_attr = "val"
 	for i, tc := range testCases {
 		t.Run(fmt.Sprintf("%d:%s", i, tc.Diag.Description()), func(t *testing.T) {
 			var diags Diagnostics
+
+			origAddr := tc.Diag.Description().Address
 			diags = diags.Append(tc.Diag)
-			gotDiags := diags.InConfigBody(f.Body)
+
+			gotDiags := diags.InConfigBody(f.Body, "test.addr")
 			gotRange := gotDiags[0].Source().Subject
+			gotAddr := gotDiags[0].Description().Address
+
+			switch {
+			case origAddr != "":
+				if gotAddr != origAddr {
+					t.Errorf("original diagnostic address modified from %s to %s", origAddr, gotAddr)
+				}
+			case gotAddr != "test.addr":
+				t.Error("missing detail address")
+			}
 
 			for _, problem := range deep.Equal(gotRange, tc.ExpectedRange) {
 				t.Error(problem)
diff --git a/tfdiags/diagnostic.go b/tfdiags/diagnostic.go
index a7699cf01..d84fa666f 100644
--- a/tfdiags/diagnostic.go
+++ b/tfdiags/diagnostic.go
@@ -25,6 +25,7 @@ const (
 )
 
 type Description struct {
+	Address string
 	Summary string
 	Detail  string
 }
diff --git a/tfdiags/diagnostic_base.go b/tfdiags/diagnostic_base.go
index 50bf9d8eb..04e56773d 100644
--- a/tfdiags/diagnostic_base.go
+++ b/tfdiags/diagnostic_base.go
@@ -9,6 +9,7 @@ type diagnosticBase struct {
 	severity Severity
 	summary  string
 	detail   string
+	address  string
 }
 
 func (d diagnosticBase) Severity() Severity {
@@ -19,6 +20,7 @@ func (d diagnosticBase) Description() Description {
 	return Description{
 		Summary: d.summary,
 		Detail:  d.detail,
+		Address: d.address,
 	}
 }