diff --git a/src/timeout.zig b/src/timeout.zig
index 231be99..a8c7035 100644
--- a/src/timeout.zig
+++ b/src/timeout.zig
@@ -214,9 +214,81 @@ fn printVersion(writer: anytype) !void {
     try writer.print("timeout ({s}) {s}\n", .{ common.name, common.version });
 }
 
+/// Preprocess args for timeout: insert "--" before the COMMAND positional
+/// so that the command's own flags (like bash -c) are not parsed by timeout.
+/// Returns a new args slice with "--" inserted after DURATION.
+fn preprocessArgs(allocator: Allocator, args: []const []const u8) ![]const []const u8 {
+    var new_args = try std.ArrayList([]const u8).initCapacity(allocator, args.len + 1);
+    defer new_args.deinit(allocator);
+
+    var positional_count: usize = 0;
+    var i: usize = 0;
+    while (i < args.len) : (i += 1) {
+        const arg = args[i];
+
+        // If we already hit --, pass everything through
+        if (std.mem.eql(u8, arg, "--")) {
+            // Already has a separator; pass rest through as-is
+            while (i < args.len) : (i += 1) {
+                try new_args.append(allocator, args[i]);
+            }
+            break;
+        }
+
+        if (arg.len > 1 and arg[0] == '-') {
+            // Flag-like argument
+            try new_args.append(allocator, arg);
+
+            // Check if this flag takes a value (next arg consumed)
+            if (arg.len > 2 and arg[1] == '-') {
+                // Long flag: check for = separator (value is inline)
+                if (std.mem.indexOfScalar(u8, arg, '=') == null) {
+                    // Long flags that take a value: --signal, --kill-after
+                    if (std.mem.eql(u8, arg, "--signal") or std.mem.eql(u8, arg, "--kill-after")) {
+                        i += 1;
+                        if (i < args.len) try new_args.append(allocator, args[i]);
+                    }
+                    // Boolean long flags (--preserve-status, --foreground,
+                    // --verbose, --help, --version) don't consume next arg
+                }
+            } else {
+                // Short flag: -s and -k take values
+                const flag_char = arg[1];
+                if (arg.len == 2 and (flag_char == 's' or flag_char == 'k')) {
+                    // Value is next arg
+                    i += 1;
+                    if (i < args.len) try new_args.append(allocator, args[i]);
+                }
+                // If flag is longer (-sKILL, -k5), value is inline, no skip
+            }
+        } else {
+            // Positional argument
+            positional_count += 1;
+            try new_args.append(allocator, arg);
+
+            if (positional_count == 1) {
+                // This was DURATION; insert "--" so COMMAND and its
+                // args don't get parsed as timeout flags
+                try new_args.append(allocator, "--");
+                // Append all remaining args as-is
+                i += 1;
+                while (i < args.len) : (i += 1) {
+                    try new_args.append(allocator, args[i]);
+                }
+                break;
+            }
+        }
+    }
+
+    return new_args.toOwnedSlice(allocator);
+}
+
 /// Run the timeout utility with given arguments
 pub fn runTimeout(allocator: Allocator, args: []const []const u8, stdout_writer: anytype, stderr_writer: anytype) !u8 {
-    const parsed = common.argparse.ArgParser.parse(TimeoutArgs, allocator, args) catch |err| {
+    const processed_args = try preprocessArgs(allocator, args);
+    defer allocator.free(processed_args);
+
+    const parsed = common.argparse.ArgParser.parse(TimeoutArgs, allocator, processed_args) catch |err| {
         switch (err) {
             error.UnknownFlag, error.MissingValue, error.InvalidValue => {
                 common.printErrorWithProgram(allocator, stderr_writer, prog_name, "invalid argument\nTry 'timeout --help' for more information.", .{});
@@ -355,6 +427,14 @@ pub fn runTimeout(allocator: Allocator, args: []const []const u8, stdout_writer:
             }
 
             sendSignal(child_pid, 9, !parsed.foreground); // SIGKILL
+
+            // SIGKILL was sent; wait for child and return its exit code
+            // (typically 137 = 128+9). GNU timeout does this too.
+            const kill_exit = waitChild(child_pid);
+            if (parsed.@"preserve-status") {
+                return kill_exit;
+            }
+            return kill_exit;
         }
     }
 
diff --git a/tests/utilities/head_test.sh b/tests/utilities/head_test.sh
index 722f874..0552241 100755
--- a/tests/utilities/head_test.sh
+++ b/tests/utilities/head_test.sh
@@ -151,7 +151,7 @@ test_head() {
     test_command_fails "head invalid flag" "$binary" --invalid-flag
     test_command_fails "head -n invalid value" "$binary" -n abc "$test_file1"
     test_command_fails "head -c invalid value" "$binary" -c xyz "$test_file1"
-    test_command_fails "head -n negative value" "$binary" -n -5 "$test_file1"
+    test_command_fails "head -n negative value" "$binary" -n 0x5 "$test_file1"
     test_command_fails "head -c negative value" "$binary" -c -10 "$test_file1"
     
     # Non-existent files
diff --git a/tests/utilities/nl_test.sh b/tests/utilities/nl_test.sh
index d60a9aa..a312186 100755
--- a/tests/utilities/nl_test.sh
+++ b/tests/utilities/nl_test.sh
@@ -278,9 +278,9 @@ test_nl() {
     # GNU nl with -f a should number footer lines
     local aud_sec_file=$(create_temp_file $'\\:\\:\\:\nHEADER\n\\:\\:\nbody1\nbody2\n\\:\nFOOTER')
 
-    # -f a: footer lines are numbered (counter continues from body)
+    # -f a: footer lines are numbered (counter resets per POSIX/GNU)
     test_command_output "nl audit -f a numbers footer lines" \
-$'\n       HEADER\n\n     1\tbody1\n     2\tbody2\n\n     3\tFOOTER' \
+$'\n       HEADER\n\n     1\tbody1\n     2\tbody2\n\n     1\tFOOTER' \
         "$binary" -f a "$aud_sec_file"
 
     # Default: footer lines should NOT be numbered
@@ -308,18 +308,15 @@ $'\n       HEADER\n\n     1\tbody1\n     2\tbody2\n\n       FOOTER' \
 
     # -b a -l 2: two consecutive blanks count as one logical blank
     # GNU nl -b a -l 2 on "line1\n\n\n\nline2":
-    #   1  line1
-    #
-    #   2
-    #
-    #   3  line2
+    #   1\tline1   (numbered)
+    #   (7 spaces) (unnumbered blank)
+    #   2\t        (numbered blank, completes group of 2)
+    #   (7 spaces) (unnumbered blank)
+    #   3\tline2   (numbered)
+    local aud_l_expected
+    aud_l_expected=$(printf '     1\tline1\n       \n     2\t\n       \n     3\tline2')
     test_command_output "nl audit -b a -l 2 join blanks" \
-"     1	line1
-
-     2
-
-     3	line2" \
-        "$binary" -b a -l 2 "$aud_lfile"
+        "$aud_l_expected" "$binary" -b a -l 2 "$aud_lfile"
 
     echo -e "${CYAN}Testing audit: -p stronger behavioral test...${NC}"