diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5f0b5607..bd3c3941 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -115,6 +115,8 @@
 
 ### Unreleased
 
+- On windows all paths in the `ProjectCompilerOutput` are now slashed by default
+  [#1540](https://github.com/gakonst/ethers-rs/pull/1540)
 - `ArtifactOutput::write_extras` now takes the `Artifacts` directly
   [#1491](https://github.com/gakonst/ethers-rs/pull/1491)
 - Make `ethers-solc` optional dependency of `ethers`, needs `ethers-solc` feature to activate
diff --git a/ethers-solc/src/artifact_output/mod.rs b/ethers-solc/src/artifact_output/mod.rs
index 9ca5dcf3..11759fae 100644
--- a/ethers-solc/src/artifact_output/mod.rs
+++ b/ethers-solc/src/artifact_output/mod.rs
@@ -42,6 +42,22 @@ pub struct ArtifactId {
 }
 
 impl ArtifactId {
+    /// Converts any `\\` separators in the `path` to `/`
+    pub fn slash_paths(&mut self) {
+        #[cfg(windows)]
+        {
+            use path_slash::PathBufExt;
+            self.path = self.path.to_slash_lossy().as_ref().into();
+            self.source = self.source.to_slash_lossy().as_ref().into();
+        }
+    }
+
+    /// Convenience function fo [`Self::slash_paths()`]
+    pub fn with_slashed_paths(mut self) -> Self {
+        self.slash_paths();
+        self
+    }
+
     /// Returns a <filename>:<name> slug that identifies an artifact
     ///
     /// Note: This identifier is not necessarily unique. If two contracts have the same name, they
@@ -178,6 +194,18 @@ impl<T: Serialize> Artifacts<T> {
 }
 
 impl<T> Artifacts<T> {
+    /// Converts all `\\` separators in _all_ paths to `/`
+    pub fn slash_paths(&mut self) {
+        #[cfg(windows)]
+        {
+            use path_slash::PathExt;
+            self.0 = std::mem::take(&mut self.0)
+                .into_iter()
+                .map(|(path, files)| (Path::new(&path).to_slash_lossy().to_string(), files))
+                .collect()
+        }
+    }
+
     pub fn into_inner(self) -> ArtifactsMap<T> {
         self.0
     }
@@ -250,7 +278,8 @@ impl<T> Artifacts<T> {
                                 name,
                                 source: source.clone(),
                                 version: artifact.version,
-                            },
+                            }
+                            .with_slashed_paths(),
                             artifact.artifact,
                         )
                     })
diff --git a/ethers-solc/src/compile/output/contracts.rs b/ethers-solc/src/compile/output/contracts.rs
index 7e17a15a..09aab711 100644
--- a/ethers-solc/src/compile/output/contracts.rs
+++ b/ethers-solc/src/compile/output/contracts.rs
@@ -15,6 +15,17 @@ use std::{collections::BTreeMap, ops::Deref, path::Path};
 pub struct VersionedContracts(pub FileToContractsMap<Vec<VersionedContract>>);
 
 impl VersionedContracts {
+    /// Converts all `\\` separators in _all_ paths to `/`
+    pub fn slash_paths(&mut self) {
+        #[cfg(windows)]
+        {
+            use path_slash::PathExt;
+            self.0 = std::mem::take(&mut self.0)
+                .into_iter()
+                .map(|(path, files)| (Path::new(&path).to_slash_lossy().to_string(), files))
+                .collect()
+        }
+    }
     pub fn is_empty(&self) -> bool {
         self.0.is_empty()
     }
diff --git a/ethers-solc/src/compile/output/mod.rs b/ethers-solc/src/compile/output/mod.rs
index 298a0680..bddb0890 100644
--- a/ethers-solc/src/compile/output/mod.rs
+++ b/ethers-solc/src/compile/output/mod.rs
@@ -34,6 +34,19 @@ pub struct ProjectCompileOutput<T: ArtifactOutput = ConfigurableArtifacts> {
 }
 
 impl<T: ArtifactOutput> ProjectCompileOutput<T> {
+    /// Converts all `\\` separators in _all_ paths to `/`
+    pub fn slash_paths(&mut self) {
+        self.compiler_output.slash_paths();
+        self.compiled_artifacts.slash_paths();
+        self.cached_artifacts.slash_paths();
+    }
+
+    /// Convenience function fo [`Self::slash_paths()`]
+    pub fn with_slashed_paths(mut self) -> Self {
+        self.slash_paths();
+        self
+    }
+
     /// All artifacts together with their contract file name and name `<file name>:<name>`
     ///
     /// This returns a chained iterator of both cached and recompiled contract artifacts
@@ -386,6 +399,12 @@ pub struct AggregatedCompilerOutput {
 }
 
 impl AggregatedCompilerOutput {
+    /// Converts all `\\` separators in _all_ paths to `/`
+    pub fn slash_paths(&mut self) {
+        self.sources.slash_paths();
+        self.contracts.slash_paths();
+    }
+
     /// Whether the output contains a compiler error
     pub fn has_error(&self) -> bool {
         self.errors.iter().any(|err| err.severity.is_error())
diff --git a/ethers-solc/src/compile/output/sources.rs b/ethers-solc/src/compile/output/sources.rs
index b1f52a53..32e0ed31 100644
--- a/ethers-solc/src/compile/output/sources.rs
+++ b/ethers-solc/src/compile/output/sources.rs
@@ -9,6 +9,18 @@ use std::{collections::BTreeMap, path::Path};
 pub struct VersionedSourceFiles(pub BTreeMap<String, Vec<VersionedSourceFile>>);
 
 impl VersionedSourceFiles {
+    /// Converts all `\\` separators in _all_ paths to `/`
+    pub fn slash_paths(&mut self) {
+        #[cfg(windows)]
+        {
+            use path_slash::PathExt;
+            self.0 = std::mem::take(&mut self.0)
+                .into_iter()
+                .map(|(path, files)| (Path::new(&path).to_slash_lossy().to_string(), files))
+                .collect()
+        }
+    }
+
     pub fn is_empty(&self) -> bool {
         self.0.is_empty()
     }
diff --git a/ethers-solc/src/compile/project.rs b/ethers-solc/src/compile/project.rs
index 5c6e8769..5275efbe 100644
--- a/ethers-solc/src/compile/project.rs
+++ b/ethers-solc/src/compile/project.rs
@@ -207,15 +207,28 @@ impl<'a, T: ArtifactOutput> ProjectCompiler<'a, T> {
     /// let output = project.compile().unwrap();
     /// ```
     pub fn compile(self) -> Result<ProjectCompileOutput<T>> {
+        let slash_paths = self.project.slash_paths;
+
         // drive the compiler statemachine to completion
-        self.preprocess()?.compile()?.write_artifacts()?.write_cache()
+        let mut output = self.preprocess()?.compile()?.write_artifacts()?.write_cache()?;
+
+        if slash_paths {
+            // ensures we always use `/` paths
+            output.slash_paths();
+        }
+
+        Ok(output)
     }
 
     /// Does basic preprocessing
     ///   - sets proper source unit names
     ///   - check cache
     fn preprocess(self) -> Result<PreprocessedState<'a, T>> {
-        let Self { edges, project, sources, sparse_output } = self;
+        let Self { edges, project, mut sources, sparse_output } = self;
+
+        // convert paths on windows to ensure consistency with the `CompilerOutput` `solc` emits,
+        // which is unix style `/`
+        sources.slash_paths();
 
         let mut cache = ArtifactsCache::new(project, edges)?;
         // retain and compile only dirty sources and all their imports
@@ -344,6 +357,32 @@ enum CompilerSources {
 }
 
 impl CompilerSources {
+    /// Converts all `\\` separators to `/`
+    ///
+    /// This effectively ensures that `solc` can find imported files like `/src/Cheats.sol` in the
+    /// VFS (the `CompilerInput` as json) under `src/Cheats.sol`.
+    fn slash_paths(&mut self) {
+        #[cfg(windows)]
+        {
+            use path_slash::PathBufExt;
+
+            fn slash_versioned_sources(v: &mut VersionedSources) {
+                for (_, (_, sources)) in v {
+                    *sources = std::mem::take(sources)
+                        .into_iter()
+                        .map(|(path, source)| {
+                            (PathBuf::from(path.to_slash_lossy().as_ref()), source)
+                        })
+                        .collect()
+                }
+            }
+
+            match self {
+                CompilerSources::Sequential(v) => slash_versioned_sources(v),
+                CompilerSources::Parallel(v, _) => slash_versioned_sources(v),
+            };
+        }
+    }
     /// Filters out all sources that don't need to be compiled, see [`ArtifactsCache::filter`]
     fn filtered<T: ArtifactOutput>(self, cache: &mut ArtifactsCache<T>) -> FilteredCompilerSources {
         fn filtered_sources<T: ArtifactOutput>(
diff --git a/ethers-solc/src/config.rs b/ethers-solc/src/config.rs
index 75dc4d9a..2e7b91d6 100644
--- a/ethers-solc/src/config.rs
+++ b/ethers-solc/src/config.rs
@@ -8,6 +8,7 @@ use crate::{
 };
 
 use crate::artifacts::output_selection::ContractOutputSelection;
+
 use serde::{Deserialize, Serialize};
 use std::{
     collections::{BTreeSet, HashSet},
@@ -145,6 +146,28 @@ impl ProjectPathsConfig {
         Ok(Source::read_all_files(self.input_files())?)
     }
 
+    /// Converts all `\\` separators in _all_ paths to `/`
+    pub fn slash_paths(&mut self) {
+        #[cfg(windows)]
+        {
+            use path_slash::PathBufExt;
+
+            let slashed = |p: &mut PathBuf| {
+                *p = p.to_slash_lossy().as_ref().into();
+            };
+            slashed(&mut self.root);
+            slashed(&mut self.cache);
+            slashed(&mut self.artifacts);
+            slashed(&mut self.build_infos);
+            slashed(&mut self.sources);
+            slashed(&mut self.tests);
+            slashed(&mut self.scripts);
+
+            self.libraries.iter_mut().for_each(slashed);
+            self.remappings.iter_mut().for_each(Remapping::slash_path);
+        }
+    }
+
     /// Attempts to resolve an `import` from the given working directory.
     ///
     /// The `cwd` path is the parent dir of the file that includes the `import`
diff --git a/ethers-solc/src/lib.rs b/ethers-solc/src/lib.rs
index ee72845b..0e39c8a7 100644
--- a/ethers-solc/src/lib.rs
+++ b/ethers-solc/src/lib.rs
@@ -78,6 +78,10 @@ pub struct Project<T: ArtifactOutput = ConfigurableArtifacts> {
     solc_jobs: usize,
     /// Offline mode, if set, network access (download solc) is disallowed
     pub offline: bool,
+    /// Windows only config value to ensure the all paths use `/` instead of `\\`, same as `solc`
+    ///
+    /// This is a noop on other platforms
+    pub slash_paths: bool,
 }
 
 impl Project {
@@ -531,6 +535,8 @@ pub struct ProjectBuilder<T: ArtifactOutput = ConfigurableArtifacts> {
     auto_detect: bool,
     /// Use offline mode
     offline: bool,
+    /// Whether to slash paths of the `ProjectCompilerOutput`
+    slash_paths: bool,
     /// handles all artifacts related tasks
     artifacts: T,
     /// Which error codes to ignore
@@ -552,6 +558,7 @@ impl<T: ArtifactOutput> ProjectBuilder<T> {
             no_artifacts: false,
             auto_detect: true,
             offline: false,
+            slash_paths: true,
             artifacts,
             ignored_error_codes: Vec::new(),
             allowed_paths: vec![],
@@ -626,6 +633,15 @@ impl<T: ArtifactOutput> ProjectBuilder<T> {
         self
     }
 
+    /// Sets whether to slash all paths on windows
+    ///
+    /// If set to `true` all `\\` separators are replaced with `/`, same as solc
+    #[must_use]
+    pub fn set_slashed_paths(mut self, slashed_paths: bool) -> Self {
+        self.slash_paths = slashed_paths;
+        self
+    }
+
     /// Disables writing artifacts to disk
     #[must_use]
     pub fn no_artifacts(self) -> Self {
@@ -684,6 +700,7 @@ impl<T: ArtifactOutput> ProjectBuilder<T> {
             solc_jobs,
             offline,
             build_info,
+            slash_paths,
             ..
         } = self;
         ProjectBuilder {
@@ -694,6 +711,7 @@ impl<T: ArtifactOutput> ProjectBuilder<T> {
             no_artifacts,
             auto_detect,
             offline,
+            slash_paths,
             artifacts,
             ignored_error_codes,
             allowed_paths,
@@ -736,9 +754,15 @@ impl<T: ArtifactOutput> ProjectBuilder<T> {
             solc_jobs,
             offline,
             build_info,
+            slash_paths,
         } = self;
 
-        let paths = paths.map(Ok).unwrap_or_else(ProjectPathsConfig::current_hardhat)?;
+        let mut paths = paths.map(Ok).unwrap_or_else(ProjectPathsConfig::current_hardhat)?;
+
+        if slash_paths {
+            // ensures we always use `/` paths
+            paths.slash_paths();
+        }
 
         let solc = solc.unwrap_or_default();
         let solc_config = solc_config.unwrap_or_else(|| SolcConfig::builder().build());
@@ -761,6 +785,7 @@ impl<T: ArtifactOutput> ProjectBuilder<T> {
             allowed_lib_paths: allowed_paths.into(),
             solc_jobs: solc_jobs.unwrap_or_else(::num_cpus::get),
             offline,
+            slash_paths,
         })
     }
 }
diff --git a/ethers-solc/src/remappings.rs b/ethers-solc/src/remappings.rs
index b63f564c..cbeea7b0 100644
--- a/ethers-solc/src/remappings.rs
+++ b/ethers-solc/src/remappings.rs
@@ -1,4 +1,5 @@
 use crate::utils;
+
 use serde::{Deserialize, Serialize};
 use std::{
     collections::{hash_map::Entry, HashMap},
@@ -224,6 +225,15 @@ impl Remapping {
             .map(|(name, path)| Remapping { name, path: format!("{}/", path.display()) })
             .collect()
     }
+
+    /// Converts any `\\` separators in the `path` to `/`
+    pub fn slash_path(&mut self) {
+        #[cfg(windows)]
+        {
+            use path_slash::PathExt;
+            self.path = Path::new(&self.path).to_slash_lossy().to_string();
+        }
+    }
 }
 
 /// A relative [`Remapping`] that's aware of the current location
@@ -263,7 +273,7 @@ impl RelativeRemapping {
 impl fmt::Display for RelativeRemapping {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let mut s = {
-            #[cfg(target_os = "windows")]
+            #[cfg(windows)]
             {
                 // ensure we have `/` slashes on windows
                 use path_slash::PathExt;
diff --git a/ethers-solc/src/utils.rs b/ethers-solc/src/utils.rs
index 487055cf..a14e6d27 100644
--- a/ethers-solc/src/utils.rs
+++ b/ethers-solc/src/utils.rs
@@ -1,5 +1,6 @@
 //! Utility functions
 
+use cfg_if::cfg_if;
 use std::{
     collections::HashSet,
     ops::Range,
@@ -157,9 +158,22 @@ pub fn is_local_source_name(libs: &[impl AsRef<Path>], source: impl AsRef<Path>)
 }
 
 /// Canonicalize the path, platform-agnostic
+///
+/// On windows this will ensure the path only consists of `/` separators
 pub fn canonicalize(path: impl AsRef<Path>) -> Result<PathBuf, SolcIoError> {
     let path = path.as_ref();
-    dunce::canonicalize(&path).map_err(|err| SolcIoError::new(err, path))
+    cfg_if! {
+        if #[cfg(windows)] {
+            let res = dunce::canonicalize(path).map(|p| {
+                use path_slash::PathBufExt;
+                PathBuf::from(p.to_slash_lossy().as_ref())
+            });
+        } else {
+         let res = dunce::canonicalize(path);
+        }
+    };
+
+    res.map_err(|err| SolcIoError::new(err, path))
 }
 
 /// Returns the same path config but with canonicalized paths.