diff --git a/fuzzers/libfuzzer_libpng_accounting/src/lib.rs b/fuzzers/libfuzzer_libpng_accounting/src/lib.rs
index beb6fc0d45..41cb95e07c 100644
--- a/fuzzers/libfuzzer_libpng_accounting/src/lib.rs
+++ b/fuzzers/libfuzzer_libpng_accounting/src/lib.rs
@@ -75,7 +75,13 @@ struct Opt {
     #[arg(short = 'a', long, help = "Specify a remote broker", name = "REMOTE")]
     remote_broker_addr: Option<SocketAddr>,
 
-    #[arg(short, long, help = "Set an initial corpus directory", name = "INPUT")]
+    #[arg(
+        short,
+        long,
+        help = "Set an initial corpus directory",
+        name = "INPUT",
+        required = true
+    )]
     input: Vec<PathBuf>,
 
     #[arg(
diff --git a/fuzzers/libfuzzer_libpng_centralized/src/lib.rs b/fuzzers/libfuzzer_libpng_centralized/src/lib.rs
index d4a2afc432..0da15f16e4 100644
--- a/fuzzers/libfuzzer_libpng_centralized/src/lib.rs
+++ b/fuzzers/libfuzzer_libpng_centralized/src/lib.rs
@@ -73,7 +73,13 @@ struct Opt {
     #[arg(short = 'a', long, help = "Specify a remote broker", name = "REMOTE")]
     remote_broker_addr: Option<SocketAddr>,
 
-    #[arg(short, long, help = "Set an initial corpus directory", name = "INPUT")]
+    #[arg(
+        short,
+        long,
+        help = "Set an initial corpus directory",
+        name = "INPUT",
+        required = true
+    )]
     input: Vec<PathBuf>,
 
     #[arg(
diff --git a/fuzzers/libfuzzer_libpng_launcher/src/lib.rs b/fuzzers/libfuzzer_libpng_launcher/src/lib.rs
index 9765761f4f..39fa57b2f3 100644
--- a/fuzzers/libfuzzer_libpng_launcher/src/lib.rs
+++ b/fuzzers/libfuzzer_libpng_launcher/src/lib.rs
@@ -73,7 +73,13 @@ struct Opt {
     #[arg(short = 'a', long, help = "Specify a remote broker", name = "REMOTE")]
     remote_broker_addr: Option<SocketAddr>,
 
-    #[arg(short, long, help = "Set an initial corpus directory", name = "INPUT")]
+    #[arg(
+        short,
+        long,
+        help = "Set an initial corpus directory",
+        name = "INPUT",
+        required = true
+    )]
     input: Vec<PathBuf>,
 
     #[arg(
diff --git a/fuzzers/libfuzzer_libpng_norestart/src/lib.rs b/fuzzers/libfuzzer_libpng_norestart/src/lib.rs
index 254b3595b6..4fb7e39ae6 100644
--- a/fuzzers/libfuzzer_libpng_norestart/src/lib.rs
+++ b/fuzzers/libfuzzer_libpng_norestart/src/lib.rs
@@ -73,7 +73,13 @@ struct Opt {
     #[arg(short = 'a', long, help = "Specify a remote broker", name = "REMOTE")]
     remote_broker_addr: Option<SocketAddr>,
 
-    #[arg(short, long, help = "Set an the corpus directories", name = "INPUT")]
+    #[arg(
+        short,
+        long,
+        help = "Set an the corpus directories",
+        name = "INPUT",
+        required = true
+    )]
     input: Vec<PathBuf>,
 
     #[arg(