diff --git a/lib/src/global_packages.dart b/lib/src/global_packages.dart
index d8cdef6..9d79a16 100644
--- a/lib/src/global_packages.dart
+++ b/lib/src/global_packages.dart
@@ -732,35 +732,18 @@
       }
     }
 
-    // If the script was built to a snapshot, just try to invoke that
-    // directly and skip pub global run entirely.
-    String invocation;
     late String binstub;
+    // Batch files behave in funky ways if they are modified while updating.
+    // To ensure that the byte-offsets of everything stays the same even if the
+    // snapshot filename changes we insert some padding in lines containing the
+    // snapshot.
+    // 260 is the maximal short path length on Windows. Hopefully that is
+    // enough.
+    final padding = ' ' * (260 - snapshot.length);
+    // We need an absolute path since relative ones won't be relative to the
+    // right directory when the user runs this.
+    snapshot = p.absolute(snapshot);
     if (Platform.isWindows) {
-      if (fileExists(snapshot)) {
-        // We expect absolute paths from the precompiler since relative ones
-        // won't be relative to the right directory when the user runs this.
-        assert(p.isAbsolute(snapshot));
-        invocation = '''
-if exist "$snapshot" (
-  call dart "$snapshot" %*
-  rem The VM exits with code 253 if the snapshot version is out-of-date.
-  rem If it is, we need to delete it and run "pub global" manually.
-  if not errorlevel 253 (
-    goto error
-  )
-  dart pub global run ${package.name}:$script %*
-) else (
-  dart pub global run ${package.name}:$script %*
-)
-goto eof
-:error
-exit /b %errorlevel%
-:eof
-''';
-      } else {
-        invocation = 'dart pub global run ${package.name}:$script %*';
-      }
       binstub = '''
 @echo off
 rem This file was created by pub v${sdk.version}.
@@ -768,14 +751,30 @@
 rem Version: ${package.version}
 rem Executable: $executable
 rem Script: $script
-$invocation
+if exist "$snapshot" $padding(
+  call dart "$snapshot" $padding%*
+  rem The VM exits with code 253 if the snapshot version is out-of-date.
+  rem If it is, we need to delete it and run "pub global" manually.
+  if not errorlevel 253 (
+    goto error
+  )
+  call dart pub global run ${package.name}:$script %*
+) else (
+  call dart pub global run ${package.name}:$script %*
+)
+goto eof
+:error
+exit /b %errorlevel%
+:eof
 ''';
     } else {
-      if (fileExists(snapshot)) {
-        // We expect absolute paths from the precompiler since relative ones
-        // won't be relative to the right directory when the user runs this.
-        assert(p.isAbsolute(snapshot));
-        invocation = '''
+      binstub = '''
+#!/usr/bin/env sh
+# This file was created by pub v${sdk.version}.
+# Package: ${package.name}
+# Version: ${package.version}
+# Executable: $executable
+# Script: $script
 if [ -f $snapshot ]; then
   dart "$snapshot" "\$@"
   # The VM exits with code 253 if the snapshot version is out-of-date.
@@ -789,18 +788,6 @@
   dart pub global run ${package.name}:$script "\$@"
 fi
 ''';
-      } else {
-        invocation = 'dart pub global run ${package.name}:$script "\$@"';
-      }
-      binstub = '''
-#!/usr/bin/env sh
-# This file was created by pub v${sdk.version}.
-# Package: ${package.name}
-# Version: ${package.version}
-# Executable: $executable
-# Script: $script
-$invocation
-''';
     }
 
     // Write the binstub to a temporary location, make it executable and move