diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7a3e8a8..e7f1789 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -163,7 +163,7 @@ jobs:
       - name: deadcode
         run: |
           go install golang.org/x/tools/cmd/deadcode@latest
-          deadcode ./... 2>&1 | head -50
+          deadcode ./...
 
   # -------------------------------------------------------------------------
   # Duplication detection — jscpd.
@@ -172,13 +172,13 @@ jobs:
     name: duplication
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
         with:
           node-version: '20'
       - name: jscpd
         run: |
-          npx jscpd --min-lines 5 --min-tokens 50 --reporters console --blame . 2>&1 | head -50
+          npx --yes jscpd@5.0.12 --min-lines 5 --min-tokens 50 --reporters console --blame .
 
   # -------------------------------------------------------------------------
   # Fuzz the diff parser, which consumes untrusted/adversarial unified-diff
@@ -196,9 +196,9 @@ jobs:
           cache: true
       - name: Run fuzz targets
         run: |
-          go test -fuzz=FuzzParseDiff        -fuzztime=60s ./internal/diff
-          go test -fuzz=FuzzParseHunkHeader  -fuzztime=60s ./internal/diff
-          go test -fuzz=FuzzParseUnifiedDiff -fuzztime=60s ./internal/diff
+          go test -fuzz=FuzzParseDiff        -fuzztime=55s ./internal/diff
+          go test -fuzz=FuzzParseHunkHeader  -fuzztime=55s ./internal/diff
+          go test -fuzz=FuzzParseUnifiedDiff -fuzztime=55s ./internal/diff
 
   # -------------------------------------------------------------------------
   # Cross-platform build matrix — only for repos that produce a binary.
diff --git a/internal/diff/diff.go b/internal/diff/diff.go
index e3f5a72..e355822 100644
--- a/internal/diff/diff.go
+++ b/internal/diff/diff.go
@@ -131,10 +131,12 @@ func parseFileChunk(chunk string) File {
 			file.OldPath = strings.TrimPrefix(line, "--- a/")
 		case strings.HasPrefix(line, "--- /dev/null"):
 			file.Added = true
+			file.Deleted = false
 		case strings.HasPrefix(line, "+++ b/"):
 			file.Path = strings.TrimPrefix(line, "+++ b/")
 		case strings.HasPrefix(line, "+++ /dev/null"):
 			file.Deleted = true
+			file.Added = false
 		case strings.HasPrefix(line, "rename from "):
 			file.OldPath = strings.TrimPrefix(line, "rename from ")
 			file.Renamed = true
diff --git a/internal/diff/diff_test.go b/internal/diff/diff_test.go
index 15c1ce2..448e150 100644
--- a/internal/diff/diff_test.go
+++ b/internal/diff/diff_test.go
@@ -167,6 +167,19 @@ index abc..def 100644
 	}
 }
 
+func TestParse_NotBothAddedAndDeleted(t *testing.T) {
+	diff := `diff --git a/devnull b/devnull
+--- /dev/null
++++ /dev/null
+`
+	files := Parse(diff)
+	for _, f := range files {
+		if f.Added && f.Deleted {
+			t.Errorf("file %q should not be both added and deleted", f.Path)
+		}
+	}
+}
+
 func TestParse_Empty(t *testing.T) {
 	files := Parse("")
 	if len(files) != 0 {