diff --git a/internal/transformers/declarations/transform.go b/internal/transformers/declarations/transform.go
index ad80436fb1..2f81b28a72 100644
--- a/internal/transformers/declarations/transform.go
+++ b/internal/transformers/declarations/transform.go
@@ -10,7 +10,6 @@ import (
 	"github.com/microsoft/typescript-go/internal/modulespecifiers"
 	"github.com/microsoft/typescript-go/internal/nodebuilder"
 	"github.com/microsoft/typescript-go/internal/printer"
-	"github.com/microsoft/typescript-go/internal/scanner"
 	"github.com/microsoft/typescript-go/internal/transformers"
 	"github.com/microsoft/typescript-go/internal/tspath"
 )
@@ -468,9 +467,7 @@ func (tx *DeclarationTransformer) visitDeclarationSubtree(input *ast.Node) *ast.
 	case ast.KindTupleType:
 		result = tx.Visitor().VisitEachChild(input)
 		if result != nil {
-			startLine, _ := scanner.GetLineAndCharacterOfPosition(tx.state.currentSourceFile, input.Loc.Pos())
-			endLine, _ := scanner.GetLineAndCharacterOfPosition(tx.state.currentSourceFile, input.Loc.End())
-			if startLine == endLine {
+			if transformers.IsOriginalNodeSingleLine(tx.EmitContext(), input) {
 				tx.EmitContext().AddEmitFlags(result, printer.EFSingleLine)
 			}
 		}
diff --git a/internal/transformers/utilities.go b/internal/transformers/utilities.go
index 010af33d0a..7d4cde7862 100644
--- a/internal/transformers/utilities.go
+++ b/internal/transformers/utilities.go
@@ -5,6 +5,7 @@ import (
 
 	"github.com/microsoft/typescript-go/internal/ast"
 	"github.com/microsoft/typescript-go/internal/printer"
+	"github.com/microsoft/typescript-go/internal/scanner"
 )
 
 func IsGeneratedIdentifier(emitContext *printer.EmitContext, name *ast.IdentifierNode) bool {
@@ -245,3 +246,20 @@ func IsSimpleCopiableExpression(expression *ast.Expression) bool {
 		ast.IsKeywordKind(expression.Kind) ||
 		ast.IsIdentifier(expression)
 }
+
+func IsOriginalNodeSingleLine(emitContext *printer.EmitContext, node *ast.Node) bool {
+	if node == nil {
+		return false
+	}
+	original := emitContext.MostOriginal(node)
+	if original == nil {
+		return false
+	}
+	source := ast.GetSourceFileOfNode(original)
+	if source == nil {
+		return false
+	}
+	startLine, _ := scanner.GetLineAndCharacterOfPosition(source, original.Loc.Pos())
+	endLine, _ := scanner.GetLineAndCharacterOfPosition(source, original.Loc.End())
+	return startLine == endLine
+}
diff --git a/testdata/baselines/reference/compiler/declarationEmitAugmentationUsesCorrectSourceFile.js b/testdata/baselines/reference/compiler/declarationEmitAugmentationUsesCorrectSourceFile.js
new file mode 100644
index 0000000000..5ce8ff6983
--- /dev/null
+++ b/testdata/baselines/reference/compiler/declarationEmitAugmentationUsesCorrectSourceFile.js
@@ -0,0 +1,49 @@
+//// [tests/cases/compiler/declarationEmitAugmentationUsesCorrectSourceFile.ts] ////
+
+//// [index.d.ts]
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+
+type ShouldJustBeAny = [any][0];
+
+declare namespace knex {
+  export { Knex };
+}
+
+declare namespace Knex {
+  interface Interface {
+    method(): ShouldJustBeAny;
+  }
+}
+
+export = knex;
+
+//// [index.ts]
+import "knex";
+declare module "knex" {
+  namespace Knex {
+    function newFunc(): Knex.Interface;
+  }
+}
+
+
+
+
+//// [index.js]
+import "knex";
+
+
+//// [index.d.ts]
+import "knex";
+declare module "knex" {
+    namespace Knex {
+        function newFunc(): Knex.Interface;
+    }
+}
diff --git a/testdata/baselines/reference/compiler/declarationEmitAugmentationUsesCorrectSourceFile.symbols b/testdata/baselines/reference/compiler/declarationEmitAugmentationUsesCorrectSourceFile.symbols
new file mode 100644
index 0000000000..ce3dbfbd1a
--- /dev/null
+++ b/testdata/baselines/reference/compiler/declarationEmitAugmentationUsesCorrectSourceFile.symbols
@@ -0,0 +1,55 @@
+//// [tests/cases/compiler/declarationEmitAugmentationUsesCorrectSourceFile.ts] ////
+
+=== node_modules/knex/index.d.ts ===
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+
+type ShouldJustBeAny = [any][0];
+>ShouldJustBeAny : Symbol(ShouldJustBeAny, Decl(index.d.ts, 0, 0))
+
+declare namespace knex {
+>knex : Symbol(knex, Decl(index.d.ts, 10, 32), Decl(index.ts, 0, 14))
+
+  export { Knex };
+>Knex : Symbol(Knex, Decl(index.d.ts, 13, 10))
+}
+
+declare namespace Knex {
+>Knex : Symbol(Knex, Decl(index.d.ts, 14, 1), Decl(index.ts, 1, 23))
+
+  interface Interface {
+>Interface : Symbol(Interface, Decl(index.d.ts, 16, 24))
+
+    method(): ShouldJustBeAny;
+>method : Symbol(method, Decl(index.d.ts, 17, 23))
+>ShouldJustBeAny : Symbol(ShouldJustBeAny, Decl(index.d.ts, 0, 0))
+  }
+}
+
+export = knex;
+>knex : Symbol(knex, Decl(index.d.ts, 10, 32), Decl(index.ts, 0, 14))
+
+=== index.ts ===
+import "knex";
+declare module "knex" {
+>"knex" : Symbol(knex, Decl(index.d.ts, 10, 32), Decl(index.ts, 0, 14))
+
+  namespace Knex {
+>Knex : Symbol(Knex, Decl(index.d.ts, 14, 1), Decl(index.ts, 1, 23))
+
+    function newFunc(): Knex.Interface;
+>newFunc : Symbol(newFunc, Decl(index.ts, 2, 18))
+>Knex : Symbol(Knex, Decl(index.d.ts, 14, 1), Decl(index.ts, 1, 23))
+>Interface : Symbol(Interface, Decl(index.d.ts, 16, 24))
+  }
+}
+
+
+
diff --git a/testdata/baselines/reference/compiler/declarationEmitAugmentationUsesCorrectSourceFile.types b/testdata/baselines/reference/compiler/declarationEmitAugmentationUsesCorrectSourceFile.types
new file mode 100644
index 0000000000..59932e3351
--- /dev/null
+++ b/testdata/baselines/reference/compiler/declarationEmitAugmentationUsesCorrectSourceFile.types
@@ -0,0 +1,47 @@
+//// [tests/cases/compiler/declarationEmitAugmentationUsesCorrectSourceFile.ts] ////
+
+=== node_modules/knex/index.d.ts ===
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+
+type ShouldJustBeAny = [any][0];
+>ShouldJustBeAny : any
+
+declare namespace knex {
+  export { Knex };
+>Knex : any
+}
+
+declare namespace Knex {
+  interface Interface {
+    method(): ShouldJustBeAny;
+>method : () => any
+  }
+}
+
+export = knex;
+>knex : typeof import("knex")
+
+=== index.ts ===
+import "knex";
+declare module "knex" {
+>"knex" : typeof import("knex")
+
+  namespace Knex {
+>Knex : typeof Knex
+
+    function newFunc(): Knex.Interface;
+>newFunc : () => Interface
+>Knex : any
+  }
+}
+
+
+
diff --git a/testdata/tests/cases/compiler/declarationEmitAugmentationUsesCorrectSourceFile.ts b/testdata/tests/cases/compiler/declarationEmitAugmentationUsesCorrectSourceFile.ts
new file mode 100644
index 0000000000..015d63fe48
--- /dev/null
+++ b/testdata/tests/cases/compiler/declarationEmitAugmentationUsesCorrectSourceFile.ts
@@ -0,0 +1,40 @@
+// @strict: true
+// @module: preserve
+// @declaration: true
+
+// @filename: node_modules/knex/index.d.ts
+
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+// A bunch of random text to move the positions forward
+
+type ShouldJustBeAny = [any][0];
+
+declare namespace knex {
+  export { Knex };
+}
+
+declare namespace Knex {
+  interface Interface {
+    method(): ShouldJustBeAny;
+  }
+}
+
+export = knex;
+
+// @filename: index.ts
+
+import "knex";
+declare module "knex" {
+  namespace Knex {
+    function newFunc(): Knex.Interface;
+  }
+}
+
+