diff --git a/pkg/commands/patch/patch_modifier.go b/pkg/commands/patch/patch_modifier.go
index c2bbc60f6..e5c6d061f 100644
--- a/pkg/commands/patch/patch_modifier.go
+++ b/pkg/commands/patch/patch_modifier.go
@@ -137,12 +137,17 @@ func ModifiedPatchForLines(log *logrus.Entry, filename string, diffText string,
 }
 
 // I want to know, given a hunk, what line a given index is on
-func (hunk *PatchHunk) LineNumberOfLine(idx int) int {
-	lines := hunk.bodyLines[0 : idx-hunk.FirstLineIdx-1]
+func (hunk *PatchHunk) LineNumberOfLine(idx int) (int, error) {
+	n := idx - hunk.FirstLineIdx - 1
+	if n < 0 || len(hunk.bodyLines) <= n {
+		return -1, fmt.Errorf("line index out of range")
+	}
+
+	lines := hunk.bodyLines[0:n]
 
 	offset := nLinesWithPrefix(lines, []string{"+", " "})
 
-	return hunk.newStart + offset
+	return hunk.newStart + offset, nil
 }
 
 func nLinesWithPrefix(lines []string, chars []string) int {
diff --git a/pkg/commands/patch/patch_modifier_test.go b/pkg/commands/patch/patch_modifier_test.go
index 8b866019b..1f1eeb114 100644
--- a/pkg/commands/patch/patch_modifier_test.go
+++ b/pkg/commands/patch/patch_modifier_test.go
@@ -539,7 +539,7 @@ func TestLineNumberOfLine(t *testing.T) {
 
 	for _, s := range scenarios {
 		t.Run(s.testName, func(t *testing.T) {
-			result := s.hunk.LineNumberOfLine(s.idx)
+			result, _ := s.hunk.LineNumberOfLine(s.idx)
 			if !assert.Equal(t, s.expected, result) {
 				fmt.Println(result)
 			}
diff --git a/pkg/gui/lbl/state.go b/pkg/gui/lbl/state.go
index 8ae828923..6adb03a54 100644
--- a/pkg/gui/lbl/state.go
+++ b/pkg/gui/lbl/state.go
@@ -167,7 +167,7 @@ func (s *State) SelectedRange() (int, int) {
 	}
 }
 
-func (s *State) CurrentLineNumber() int {
+func (s *State) CurrentLineNumber() (int, error) {
 	return s.CurrentHunk().LineNumberOfLine(s.selectedLineIdx)
 }
 
diff --git a/pkg/gui/line_by_line_panel.go b/pkg/gui/line_by_line_panel.go
index 7171864f4..6f93c36b9 100644
--- a/pkg/gui/line_by_line_panel.go
+++ b/pkg/gui/line_by_line_panel.go
@@ -208,7 +208,11 @@ func (gui *Gui) handleOpenFileAtLine() error {
 		}
 
 		// need to look at current index, then work out what my hunk's header information is, and see how far my line is away from the hunk header
-		lineNumber := state.CurrentLineNumber()
+		lineNumber, err := state.CurrentLineNumber()
+		if err != nil {
+			lineNumber = 1
+		}
+
 		filenameWithLineNum := fmt.Sprintf("%s:%d", filename, lineNumber)
 		if err := gui.OSCommand.OpenFile(filenameWithLineNum); err != nil {
 			return err
@@ -279,7 +283,10 @@ func (gui *Gui) handleLineByLineEdit() error {
 		return nil
 	}
 
-	lineNumber := gui.State.Panels.LineByLine.CurrentLineNumber()
+	lineNumber, err := gui.State.Panels.LineByLine.CurrentLineNumber()
+	if err != nil {
+		lineNumber = 1
+	}
 
 	return gui.editFileAtLine(file.Name, lineNumber)
 }