diff --git a/src/js_parser/parse/parse_entry.rs b/src/js_parser/parse/parse_entry.rs
index 87c89136c8a7..264529792941 100644
--- a/src/js_parser/parse/parse_entry.rs
+++ b/src/js_parser/parse/parse_entry.rs
@@ -18,6 +18,7 @@ use crate::parser::{
     Jest, ParseStatementOptions, RuntimeFeatures, RuntimeImports, ScanPassResult, StatementScope,
     WrapMode,
 };
+use crate::scan::scan_side_effects::SideEffects;
 use bun_ast as js_ast;
 use bun_ast::DeclaredSymbol;
 use bun_ast::{B, E, Expr, G, S, Stmt};
@@ -1252,7 +1253,47 @@ impl<'a> Parser<'a> {
                 found
             };
             if let Some(found) = stmt_and_part {
-                let stmt = found.stmt;
+                let mut stmt = found.stmt;
+                // Without --minify-syntax the NODE_ENV if/else above survives
+                // as `if (<const>) {} else { X }` after DCE empties the dead
+                // arm; peel to the live arm's single statement. `to_boolean` is
+                // the same predicate `s_if` used to pick the dead arm.
+                while let js_ast::StmtData::SIf(s_if) = &stmt.data {
+                    let Some(effects) = SideEffects::to_boolean(p, &s_if.test.data) else {
+                        break;
+                    };
+                    if effects.side_effects != SideEffects::NoSideEffects {
+                        break;
+                    }
+                    let (live, dead) = if effects.value {
+                        (Some(s_if.yes), s_if.no)
+                    } else {
+                        (s_if.no, Some(s_if.yes))
+                    };
+                    let dead_is_empty = match dead {
+                        None => true,
+                        Some(d) => match d.data {
+                            js_ast::StmtData::SEmpty(_) => true,
+                            js_ast::StmtData::SBlock(block) => block.stmts.len() == 0,
+                            _ => false,
+                        },
+                    };
+                    if !dead_is_empty {
+                        break;
+                    }
+                    let Some(live_stmt) = live else { break };
+                    match live_stmt.data {
+                        js_ast::StmtData::SBlock(block) => {
+                            let body = block.stmts.slice();
+                            if body.len() != 1 {
+                                break;
+                            }
+                            stmt = body[0];
+                        }
+                        js_ast::StmtData::SEmpty(_) => break,
+                        _ => stmt = live_stmt,
+                    }
+                }
                 let part = &mut parts[found.part_idx];
                 if p.symbols.as_slice()[p.module_ref.inner_index() as usize].use_count_estimate == 1
                 {
diff --git a/test/bundler/bundler_cjs2esm.test.ts b/test/bundler/bundler_cjs2esm.test.ts
index c0860af1dfec..e2b2ffeb63f6 100644
--- a/test/bundler/bundler_cjs2esm.test.ts
+++ b/test/bundler/bundler_cjs2esm.test.ts
@@ -200,6 +200,193 @@ describe("bundler", () => {
       stdout: "development",
     },
   });
+  // https://github.com/oven-sh/bun/issues/12726
+  itBundled("cjs2esm/ModuleExportsBasedOnNodeEnvProductionNoMinify", {
+    files: {
+      "/entry.js": /* js */ `
+        import { foo } from 'lib';
+        console.log(foo);
+      `,
+      "/node_modules/lib/index.js": /* js */ `
+        'use strict';
+        if (process.env.NODE_ENV === 'production') {
+          module.exports = require('./library.prod.js')
+        } else {
+          module.exports = require('./library.dev.js')
+        }
+      `,
+      "/node_modules/lib/library.prod.js": /* js */ `
+        module.exports.foo = 'production';
+      `,
+      "/node_modules/lib/library.dev.js": /* js */ `
+        module.exports.foo = 'FAILED';
+      `,
+    },
+    cjs2esm: true,
+    env: {
+      NODE_ENV: "production",
+    },
+    run: {
+      stdout: "production",
+    },
+  });
+  itBundled("cjs2esm/ModuleExportsBasedOnNodeEnvDevelopmentNoMinify", {
+    files: {
+      "/entry.js": /* js */ `
+        import { foo } from 'lib';
+        console.log(foo);
+      `,
+      "/node_modules/lib/index.js": /* js */ `
+        'use strict';
+        if (process.env.NODE_ENV === 'production') {
+          module.exports = require('./library.prod.js')
+        } else {
+          module.exports = require('./library.dev.js')
+        }
+      `,
+      "/node_modules/lib/library.prod.js": /* js */ `
+        module.exports.foo = 'FAILED';
+      `,
+      "/node_modules/lib/library.dev.js": /* js */ `
+        module.exports.foo = 'development';
+      `,
+    },
+    cjs2esm: true,
+    env: {
+      NODE_ENV: "development",
+    },
+    run: {
+      stdout: "development",
+    },
+  });
+  itBundled("cjs2esm/ModuleExportsBasedOnNodeEnvNoBracesNoMinify", {
+    files: {
+      "/entry.js": /* js */ `
+        import { foo } from 'lib';
+        console.log(foo);
+      `,
+      "/node_modules/lib/index.js": /* js */ `
+        if (process.env.NODE_ENV === 'production')
+          module.exports = require('./library.prod.js')
+        else
+          module.exports = require('./library.dev.js')
+      `,
+      "/node_modules/lib/library.prod.js": /* js */ `
+        module.exports.foo = 'FAILED';
+      `,
+      "/node_modules/lib/library.dev.js": /* js */ `
+        module.exports.foo = 'development';
+      `,
+    },
+    cjs2esm: true,
+    env: {
+      NODE_ENV: "development",
+    },
+    run: {
+      stdout: "development",
+    },
+  });
+  itBundled("cjs2esm/ModuleExportsBasedOnDefineNumberNoMinify", {
+    files: {
+      "/entry.js": /* js */ `
+        import { foo } from 'lib';
+        console.log(foo);
+      `,
+      "/node_modules/lib/index.js": /* js */ `
+        if (__DEV__) {
+          module.exports = require('./library.dev.js')
+        } else {
+          module.exports = require('./library.prod.js')
+        }
+      `,
+      "/node_modules/lib/library.prod.js": /* js */ `
+        module.exports.foo = 'production';
+      `,
+      "/node_modules/lib/library.dev.js": /* js */ `
+        module.exports.foo = 'FAILED';
+      `,
+    },
+    cjs2esm: true,
+    define: {
+      __DEV__: "0",
+    },
+    run: {
+      stdout: "production",
+    },
+  });
+  itBundled("cjs2esm/ModuleExportsBasedOnNodeEnvElseIfChainNoMinify", {
+    files: {
+      "/entry.js": /* js */ `
+        import { foo } from 'lib';
+        console.log(foo);
+      `,
+      "/node_modules/lib/index.js": /* js */ `
+        if (process.env.NODE_ENV === 'production') {
+          module.exports = require('./library.prod.js')
+        } else if (process.env.NODE_ENV === 'test') {
+          module.exports = require('./library.test.js')
+        } else {
+          module.exports = require('./library.dev.js')
+        }
+      `,
+      "/node_modules/lib/library.prod.js": /* js */ `
+        module.exports.foo = 'FAILED';
+      `,
+      "/node_modules/lib/library.test.js": /* js */ `
+        module.exports.foo = 'FAILED';
+      `,
+      "/node_modules/lib/library.dev.js": /* js */ `
+        module.exports.foo = 'development';
+      `,
+    },
+    cjs2esm: true,
+    env: {
+      NODE_ENV: "development",
+    },
+    run: {
+      stdout: "development",
+    },
+  });
+  itBundled("cjs2esm/ReactIndexNodeEnvRedirectNoMinify", {
+    files: {
+      "/entry.js": /* js */ `
+        const react = require("react");
+        console.log(react.version);
+      `,
+      "/node_modules/react/package.json": /* json */ `
+        { "name": "react", "version": "18.3.1", "main": "./index.js" }
+      `,
+      "/node_modules/react/index.js": /* js */ `
+        'use strict';
+
+        if (process.env.NODE_ENV === 'production') {
+          module.exports = require('./cjs/react.production.min.js');
+        } else {
+          module.exports = require('./cjs/react.development.js');
+        }
+      `,
+      "/node_modules/react/cjs/react.production.min.js": /* js */ `
+        exports.version = 'FAILED';
+      `,
+      "/node_modules/react/cjs/react.development.js": /* js */ `
+        exports.version = '18.3.1-dev';
+      `,
+    },
+    target: "bun",
+    env: {
+      NODE_ENV: "development",
+    },
+    onAfterBundle(api) {
+      const code = api.readFile("out.js");
+      expect(code).not.toContain("react/index.js");
+      expect(code).not.toContain("require_react ");
+      expect(code).not.toContain("require_react(");
+      expect(code).not.toContain("react.production.min.js");
+    },
+    run: {
+      stdout: "18.3.1-dev",
+    },
+  });
   itBundled("cjs2esm/ModuleExportsEqualsRuntimeCondition", {
     files: {
       "/entry.js": /* js */ `
diff --git a/test/bundler/transpiler/jsx-dev/jsx-dev.tsx b/test/bundler/transpiler/jsx-dev/jsx-dev.tsx
index ee854a800268..03d23c878d5c 100644
--- a/test/bundler/transpiler/jsx-dev/jsx-dev.tsx
+++ b/test/bundler/transpiler/jsx-dev/jsx-dev.tsx
@@ -21,13 +21,13 @@ if (!process.env.NO_BUILD) {
   let shouldHaveJSX = process.env.CHILD_NODE_ENV === "production";
 
   if (shouldHaveJSXDev) {
-    if (!code.includes("jsx_dev_runtime.jsxDEV")) {
+    if (!code.includes("jsx-dev-runtime.development") || !code.includes("jsxDEV(")) {
       throw new Error("jsxDEV is not included");
     }
   }
 
   if (shouldHaveJSX) {
-    if (!code.includes("jsx_runtime.jsx")) {
+    if (!code.includes("jsx-runtime.production") || code.includes("jsxDEV(")) {
       throw new Error("Jsx is not included");
     }
   }
diff --git a/test/bundler/transpiler/jsx-production.tsx b/test/bundler/transpiler/jsx-production.tsx
index ee854a800268..03d23c878d5c 100644
--- a/test/bundler/transpiler/jsx-production.tsx
+++ b/test/bundler/transpiler/jsx-production.tsx
@@ -21,13 +21,13 @@ if (!process.env.NO_BUILD) {
   let shouldHaveJSX = process.env.CHILD_NODE_ENV === "production";
 
   if (shouldHaveJSXDev) {
-    if (!code.includes("jsx_dev_runtime.jsxDEV")) {
+    if (!code.includes("jsx-dev-runtime.development") || !code.includes("jsxDEV(")) {
       throw new Error("jsxDEV is not included");
     }
   }
 
   if (shouldHaveJSX) {
-    if (!code.includes("jsx_runtime.jsx")) {
+    if (!code.includes("jsx-runtime.production") || code.includes("jsxDEV(")) {
       throw new Error("Jsx is not included");
     }
   }