diff --git a/packages/utils/src/misc.ts b/packages/utils/src/misc.ts
index 640c526db7b2..a474c8e157e4 100644
--- a/packages/utils/src/misc.ts
+++ b/packages/utils/src/misc.ts
@@ -153,7 +153,7 @@ export function addContextToFrame(lines: string[], frame: StackFrame, linesOfCon
   }
 
   const maxLines = lines.length;
-  const sourceLine = Math.max(Math.min(maxLines, frame.lineno - 1), 0);
+  const sourceLine = Math.max(Math.min(maxLines - 1, frame.lineno - 1), 0);
 
   frame.pre_context = lines
     .slice(Math.max(0, sourceLine - linesOfContext), sourceLine)
diff --git a/packages/utils/test/misc.test.ts b/packages/utils/test/misc.test.ts
index 77c6441e31a1..aaac0d46c0b0 100644
--- a/packages/utils/test/misc.test.ts
+++ b/packages/utils/test/misc.test.ts
@@ -181,10 +181,20 @@ describe('addContextToFrame', () => {
       lineno: 999,
     };
     addContextToFrame(lines, frame);
-    expect(frame.pre_context).toEqual(['10: j', '11: k', '12: l', '13: m', '14: n']);
+    expect(frame.pre_context).toEqual(['9: i', '10: j', '11: k', '12: l', '13: m']);
     expect(frame.context_line).toEqual('14: n');
     expect(frame.post_context).toEqual([]);
   });
+
+  test('truncate line if too long', () => {
+    const frame: StackFrame = {
+      lineno: 1,
+    };
+    addContextToFrame(['1234567890'.repeat(100)], frame);
+    expect(frame.pre_context).toEqual([]);
+    expect(frame.context_line).toEqual(`${'1234567890'.repeat(14)} {snip}`);
+    expect(frame.post_context).toEqual([]);
+  });
 });
 
 describe('addExceptionMechanism', () => {