diff --git a/src/cli/Arguments.zig b/src/cli/Arguments.zig
index e0556a97a1..27440c8c67 100644
--- a/src/cli/Arguments.zig
+++ b/src/cli/Arguments.zig
@@ -650,7 +650,32 @@ pub fn parse(allocator: std.mem.Allocator, ctx: Command.Context, comptime cmd: C
         else
             Bunfig.OfflineMode.online;
 
-        if (args.flag("--no-install")) {
+        const has_security_provider = if (ctx.install) |install|
+            install.security_provider != null
+        else
+            false;
+
+        if (has_security_provider) {
+            if (args.flag("-i")) {
+                Output.prettyErrorln("<r><yellow>warning<r>: Autoinstall is disabled because a security provider is configured. The -i flag will be ignored.", .{});
+                Output.flush();
+            } else if (args.option("--install")) |enum_value| {
+                const requested_mode = options.GlobalCache.Map.get(enum_value) orelse
+                    (if (enum_value.len == 0) options.GlobalCache.force else null);
+
+                if (requested_mode) |mode| {
+                    if (mode != .disable) {
+                        Output.prettyErrorln("<r><yellow>warning<r>: Autoinstall is disabled because a security provider is configured. The --install={s} flag will be ignored.", .{enum_value});
+                        Output.flush();
+                    }
+                }
+            }
+
+            // disable autoinstall because it doesn't make sense we enable
+            // autoinstall when something designed to block installing packages
+            // exists...
+            ctx.debug.global_cache = .disable;
+        } else if (args.flag("--no-install")) {
             ctx.debug.global_cache = .disable;
         } else if (args.flag("-i")) {
             ctx.debug.global_cache = .fallback;
diff --git a/test/cli/run/run-autoinstall-security.test.ts b/test/cli/run/run-autoinstall-security.test.ts
new file mode 100644
index 0000000000..69abf8c48e
--- /dev/null
+++ b/test/cli/run/run-autoinstall-security.test.ts
@@ -0,0 +1,83 @@
+import { describe, expect, test } from "bun:test";
+import { bunEnv, bunExe, normalizeBunSnapshot, tempDirWithFiles } from "harness";
+
+describe("autoinstall with security provider", () => {
+  test("should disable autoinstall when security provider is configured", async () => {
+    const dir = tempDirWithFiles("autoinstall-security", {
+      "index.js": "import isEven from 'is-even'; console.log(isEven(2));",
+      "bunfig.toml": `
+[install]
+auto = "force"  # This should be overridden by security provider
+
+[install.security]
+provider = "example-security-provider"
+`,
+    });
+
+    const { stdout, stderr, exitCode } = Bun.spawnSync({
+      cmd: [bunExe(), "index.js"],
+      cwd: dir,
+      env: bunEnv,
+      stdout: "pipe",
+      stderr: "pipe",
+    });
+
+    // Should not autoinstall when security provider is set
+    expect(normalizeBunSnapshot(stderr?.toString("utf8") || "", dir)).toMatchInlineSnapshot(`
+      "error: Cannot find package 'is-even' from '<dir>/index.js'
+
+      Bun v<bun-version>+b30ae0956 (macOS arm64)"
+    `);
+    expect(exitCode).not.toBe(0);
+  });
+
+  test("should allow autoinstall without security provider", async () => {
+    const dir = tempDirWithFiles("autoinstall-no-security", {
+      "index.js": "import isEven from 'is-even'; console.log(isEven(2));",
+      "bunfig.toml": `
+[install]
+auto = "force"  # Should work without security provider
+`,
+    });
+
+    const { stdout, stderr, exitCode } = Bun.spawnSync({
+      cmd: [bunExe(), "index.js"],
+      cwd: dir,
+      env: bunEnv,
+      stdout: "pipe",
+      stderr: "pipe",
+    });
+
+    // Should autoinstall when no security provider is set
+    expect(normalizeBunSnapshot(stdout?.toString("utf8") || "", dir)).toMatchInlineSnapshot(`"true"`);
+    expect(normalizeBunSnapshot(stderr?.toString("utf8") || "", dir)).toMatchInlineSnapshot(`""`);
+    expect(exitCode).toBe(0);
+  });
+
+  test.each(["-i", "--install=force", "--install=fallback"])("CLI flag %s should be disabled when security provider is configured and show warning", async (flag) => {
+    const dir = tempDirWithFiles("autoinstall-security-cli", {
+      "index.js": "import isEven from 'is-even'; console.log(isEven(2));",
+      "bunfig.toml": `
+[install.security]
+provider = "example-security-provider"
+`,
+    });
+
+    const { stderr, exitCode } = Bun.spawnSync({
+      cmd: [bunExe(), flag, "index.js"],
+      cwd: dir,
+      env: bunEnv,
+      stdout: "pipe",
+      stderr: "pipe",
+    });
+
+    const stderrStr = stderr?.toString("utf8") || "";
+    
+    // Should show warning about autoinstall being disabled
+    expect(stderrStr).toContain("warning: Autoinstall is disabled because a security provider is configured");
+    
+    // Should not autoinstall even with explicit CLI flags when security provider is set
+    expect(stderrStr).toContain("error: Cannot find package 'is-even'");
+    expect(exitCode).not.toBe(0);
+  });
+});