diff --git a/Cargo.lock b/Cargo.lock
index 2547c7a7e..3e6edb12a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3882,6 +3882,12 @@ version = "1.0.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "57c0d7b74b563b49d38dae00a0c37d4d6de9b432382b2892f0574ddcae73fd0a"
 
+[[package]]
+name = "path-slash"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e91099d4268b0e11973f036e885d652fb0b21fedcf69738c627f94db6a44f42"
+
 [[package]]
 name = "pathdiff"
 version = "0.2.3"
@@ -5363,6 +5369,7 @@ dependencies = [
  "mockito",
  "num-bigint",
  "open",
+ "path-slash",
  "pathdiff",
  "phf",
  "predicates",
diff --git a/Cargo.toml b/Cargo.toml
index 5842c403c..eaa8e83d2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -108,6 +108,7 @@ termcolor_output = "1.0.1"
 ed25519-dalek = ">= 2.1.1"
 http = "1.0.0"
 walkdir = "2.5.0"
+path-slash = "0.2.1"
 toml_edit = "0.22.20"
 toml = "0.8.19"
 reqwest = { version = "0.12.7", default-features = false, features = ["rustls-tls"] }
diff --git a/cmd/crates/soroban-test/tests/it/build.rs b/cmd/crates/soroban-test/tests/it/build.rs
index dddf87fd8..84c42fd32 100644
--- a/cmd/crates/soroban-test/tests/it/build.rs
+++ b/cmd/crates/soroban-test/tests/it/build.rs
@@ -106,7 +106,7 @@ fn build_with_image_selects_package_by_manifest_path() {
         .arg("build")
         .arg("--image")
         .arg("docker.io/stellar/stellar-cli:latest")
-        .arg(manifest_path_arg(&add_path()))
+        .arg(format!("--manifest-path={}", add_path()))
         .arg("--print-commands-only")
         .assert()
         .success()
diff --git a/cmd/soroban-cli/Cargo.toml b/cmd/soroban-cli/Cargo.toml
index 1e1d26225..038edb213 100644
--- a/cmd/soroban-cli/Cargo.toml
+++ b/cmd/soroban-cli/Cargo.toml
@@ -61,6 +61,7 @@ serde = { workspace = true, features = ["derive"] }
 serde_json = { workspace = true }
 serde-aux = { workspace = true }
 hex = { workspace = true }
+path-slash = { workspace = true }
 num-bigint = "0.4"
 # Pinned to match the version pulled in by soroban-rpc (jsonrpsee-core) so that
 # downcasting RPC errors to `ErrorObjectOwned` resolves to the same type.
diff --git a/cmd/soroban-cli/src/commands/contract/build/container.rs b/cmd/soroban-cli/src/commands/contract/build/container.rs
index d90773827..c6299e998 100644
--- a/cmd/soroban-cli/src/commands/contract/build/container.rs
+++ b/cmd/soroban-cli/src/commands/contract/build/container.rs
@@ -16,6 +16,7 @@ use std::path::{Path, PathBuf};
 use std::process::Stdio;
 
 use cargo_metadata::MetadataCommand;
+use path_slash::PathExt as _;
 use semver::Version;
 
 use crate::commands::{container::shared, global};
@@ -282,7 +283,7 @@ fn forwarded_build_args(
             .strip_prefix(workspace_root)
             .map(Path::to_path_buf)
             .unwrap_or(abs);
-        args.push(format!("--manifest-path={}", rel.display()));
+        args.push(format!("--manifest-path={}", rel.to_slash_lossy()));
     }
     if cmd.profile != "release" {
         args.push(format!("--profile={}", cmd.profile));
@@ -767,14 +768,17 @@ mod tests {
     use super::*;
     use crate::commands::contract::build::BuildArgs;
 
-    fn ws() -> &'static Path {
-        Path::new("/tmp/ws")
+    fn ws() -> PathBuf {
+        // Routed through `std::path::absolute` (as `forwarded_build_args` itself does
+        // for `manifest_path`) so both sides of the `strip_prefix` in
+        // `forwarded_build_args` agree on drive letter/prefix on Windows.
+        std::path::absolute(Path::new("/tmp/ws")).unwrap()
     }
 
     #[test]
     fn forwarded_build_args_defaults() {
         let cmd = Cmd::default();
-        let args = forwarded_build_args(&cmd, ws(), None, true, true, true);
+        let args = forwarded_build_args(&cmd, &ws(), None, true, true, true);
         assert_eq!(args[..2], ["contract".to_string(), "build".to_string()]);
         // Default optimize=true → bare `--optimize`; no `--locked` unless asked.
         assert!(args.contains(&"--optimize".to_string()));
@@ -788,7 +792,7 @@ mod tests {
             locked: true,
             ..Cmd::default()
         };
-        let args = forwarded_build_args(&cmd, ws(), Some("contract-a"), true, true, true);
+        let args = forwarded_build_args(&cmd, &ws(), Some("contract-a"), true, true, true);
         assert!(args.contains(&"--locked".to_string()));
         assert!(args.contains(&"--package=contract-a".to_string()));
     }
@@ -800,7 +804,7 @@ mod tests {
             locked: true,
             ..Cmd::default()
         };
-        let args = forwarded_build_args(&cmd, ws(), None, false, true, true);
+        let args = forwarded_build_args(&cmd, &ws(), None, false, true, true);
         assert!(!args.iter().any(|a| a == "--locked"));
     }
 
@@ -810,7 +814,7 @@ mod tests {
         // though optimize defaults to true.
         let cmd = Cmd::default();
         assert!(cmd.build_args.optimize);
-        let args = forwarded_build_args(&cmd, ws(), None, true, false, false);
+        let args = forwarded_build_args(&cmd, &ws(), None, true, false, false);
         assert!(!args.iter().any(|a| a.starts_with("--optimize")));
     }
 
@@ -830,7 +834,7 @@ mod tests {
             },
             ..Cmd::default()
         };
-        let args = forwarded_build_args(&cmd, ws(), None, true, true, true);
+        let args = forwarded_build_args(&cmd, &ws(), None, true, true, true);
         assert!(args.contains(&"--profile=dev".to_string()));
         assert!(args.contains(&"--features=a,b".to_string()));
         assert!(args.contains(&"--all-features".to_string()));
@@ -851,7 +855,7 @@ mod tests {
             },
             ..Cmd::default()
         };
-        let args = forwarded_build_args(&cmd, ws(), None, true, true, false);
+        let args = forwarded_build_args(&cmd, &ws(), None, true, true, false);
         assert!(!args.iter().any(|a| a.starts_with("--optimize")));
     }
 
@@ -861,7 +865,7 @@ mod tests {
             manifest_path: Some(PathBuf::from("/tmp/ws/contracts/add/Cargo.toml")),
             ..Cmd::default()
         };
-        let args = forwarded_build_args(&cmd, ws(), None, true, true, true);
+        let args = forwarded_build_args(&cmd, &ws(), None, true, true, true);
         assert!(args.contains(&"--manifest-path=contracts/add/Cargo.toml".to_string()));
     }