diff --git a/src/vs/workbench/parts/debug/common/debugModel.ts b/src/vs/workbench/parts/debug/common/debugModel.ts
index d5af6df481a..397cfb5a8bd 100644
--- a/src/vs/workbench/parts/debug/common/debugModel.ts
+++ b/src/vs/workbench/parts/debug/common/debugModel.ts
@@ -562,8 +562,10 @@ export class Process implements IProcess {
 		if (this.sources.has(source.uri.toString())) {
 			source = this.sources.get(source.uri.toString());
 			source.raw = mixin(source.raw, raw);
-			// Always take the latest presentation hint from adapter #42139
-			source.raw.presentationHint = raw.presentationHint;
+			if (source.raw && raw) {
+				// Always take the latest presentation hint from adapter #42139
+				source.raw.presentationHint = raw.presentationHint;
+			}
 		} else {
 			this.sources.set(source.uri.toString(), source);
 		}