diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 63bae33d00be..bfc03a2be0b8 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -51,7 +51,7 @@ jobs:
       # TODO(konstin): Mock the venv in the installer test so we don't need this anymore
       - uses: actions/setup-python@v4
         with:
-          python-version: '3.7'
+          python-version: '3.8'
       - name: "Install Python"
         uses: actions/setup-python@v4
         with:
diff --git a/crates/puffin-cli/tests/pip_compile.rs b/crates/puffin-cli/tests/pip_compile.rs
index e75427f9374f..a1d8b4935e66 100644
--- a/crates/puffin-cli/tests/pip_compile.rs
+++ b/crates/puffin-cli/tests/pip_compile.rs
@@ -630,10 +630,10 @@ fn compile_python_37() -> Result<()> {
     Ok(())
 }
 
-/// Test that we select the last 3.7 compatible numpy version instead of trying to compile an
+/// Test that we select the last 3.8 compatible numpy version instead of trying to compile an
 /// incompatible sdist <https://github.com/astral-sh/puffin/issues/388>
 #[test]
-fn compile_numpy_py37() -> Result<()> {
+fn compile_numpy_py38() -> Result<()> {
     let temp_dir = assert_fs::TempDir::new()?;
     let cache_dir = assert_fs::TempDir::new()?;
     let venv = temp_dir.child(".venv");
@@ -653,28 +653,30 @@ fn compile_numpy_py37() -> Result<()> {
     requirements_in.write_str("numpy")?;
 
     insta::with_settings!({
-        filters => INSTA_FILTERS.to_vec()
-    }, {
-        assert_cmd_snapshot!(Command::new(get_cargo_bin(BIN_NAME))
-            .arg("pip-compile")
-            .arg("requirements.in")
-            .arg("--python-version")
-            .arg("py37")
-            .arg("--cache-dir")
-            .arg(cache_dir.path())
-            .env("VIRTUAL_ENV", venv.as_os_str())
-            .current_dir(&temp_dir), @r###"
+            filters => INSTA_FILTERS.to_vec()
+        }, {
+            assert_cmd_snapshot!(Command::new(get_cargo_bin(BIN_NAME))
+                .arg("pip-compile")
+                .arg("requirements.in")
+                .arg("--python-version")
+                .arg("py38")
+                .arg("--cache-dir")
+                .arg(cache_dir.path())
+    // Check that we select the wheel and not the sdist
+                .arg("--no-build")
+                .env("VIRTUAL_ENV", venv.as_os_str())
+                .current_dir(&temp_dir), @r###"
         success: true
         exit_code: 0
         ----- stdout -----
         # This file was autogenerated by Puffin v0.0.1 via the following command:
-        #    [BIN_PATH] pip-compile requirements.in --python-version py37 --cache-dir [CACHE_DIR]
-        numpy==1.26.2
+        #    [BIN_PATH] pip-compile requirements.in --python-version py38 --cache-dir [CACHE_DIR]
+        numpy==1.24.4
 
         ----- stderr -----
         Resolved 1 package in [TIME]
         "###);
-    });
+        });
 
     Ok(())
 }
diff --git a/crates/puffin-cli/tests/pip_sync.rs b/crates/puffin-cli/tests/pip_sync.rs
index 5161b5ab13e8..001fd730e79b 100644
--- a/crates/puffin-cli/tests/pip_sync.rs
+++ b/crates/puffin-cli/tests/pip_sync.rs
@@ -929,10 +929,10 @@ fn install_version_then_install_url() -> Result<()> {
     Ok(())
 }
 
-/// Test that we select the last 3.7 compatible numpy version instead of trying to compile an
+/// Test that we select the last 3.8 compatible numpy version instead of trying to compile an
 /// incompatible sdist <https://github.com/astral-sh/puffin/issues/388>
 #[test]
-fn install_numpy_py37() -> Result<()> {
+fn install_numpy_py38() -> Result<()> {
     let temp_dir = assert_fs::TempDir::new()?;
     let cache_dir = assert_fs::TempDir::new()?;
     let venv = temp_dir.child(".venv");
@@ -942,7 +942,7 @@ fn install_numpy_py37() -> Result<()> {
         .arg(venv.as_os_str())
         .arg("--python")
         // TODO(konstin): Mock the venv in the installer test so we don't need this anymore
-        .arg(which::which("python3.7").context("python3.7 must be installed")?)
+        .arg(which::which("python3.8").context("python3.8 must be installed")?)
         .arg("--cache-dir")
         .arg(cache_dir.path())
         .current_dir(&temp_dir)
@@ -950,20 +950,6 @@ fn install_numpy_py37() -> Result<()> {
         .success();
     venv.assert(predicates::path::is_dir());
 
-    let requirements_txt = temp_dir.child("requirements.txt");
-    requirements_txt.touch()?;
-    requirements_txt.write_str("werkzeug==2.0.0")?;
-
-    Command::new(get_cargo_bin(BIN_NAME))
-        .arg("pip-sync")
-        .arg("requirements.txt")
-        .arg("--cache-dir")
-        .arg(cache_dir.path())
-        .env("VIRTUAL_ENV", venv.as_os_str())
-        .current_dir(&temp_dir)
-        .assert()
-        .success();
-
     let requirements_txt = temp_dir.child("requirements.txt");
     requirements_txt.touch()?;
     requirements_txt.write_str("numpy")?;
diff --git a/crates/puffin-cli/tests/snapshots/pip_compile__compile_constraints_markers.snap b/crates/puffin-cli/tests/snapshots/pip_compile__compile_constraints_markers.snap
index 070d5bf3201b..58972ccecfc2 100644
--- a/crates/puffin-cli/tests/snapshots/pip_compile__compile_constraints_markers.snap
+++ b/crates/puffin-cli/tests/snapshots/pip_compile__compile_constraints_markers.snap
@@ -8,9 +8,9 @@ info:
     - "--constraint"
     - constraints.txt
     - "--cache-dir"
-    - /var/folders/bc/qlsk3t6x7c9fhhbvvcg68k9c0000gp/T/.tmp1Ts53o
+    - /tmp/.tmpzpwtXx
   env:
-    VIRTUAL_ENV: /var/folders/bc/qlsk3t6x7c9fhhbvvcg68k9c0000gp/T/.tmp1vzBQa/.venv
+    VIRTUAL_ENV: /tmp/.tmpwo1pOb/.venv
 ---
 success: true
 exit_code: 0
@@ -18,11 +18,13 @@ exit_code: 0
 # This file was autogenerated by Puffin v0.0.1 via the following command:
 #    [BIN_PATH] pip-compile requirements.in --constraint constraints.txt --cache-dir [CACHE_DIR]
 anyio==4.0.0
+exceptiongroup==1.1.3
+    # via anyio
 idna==3.4
     # via anyio
 sniffio==1.3.0
     # via anyio
 
 ----- stderr -----
-Resolved 3 packages in [TIME]
+Resolved 4 packages in [TIME]
 
diff --git a/crates/puffin-cli/tests/snapshots/pip_compile__compile_constraints_txt.snap b/crates/puffin-cli/tests/snapshots/pip_compile__compile_constraints_txt.snap
index e2b3adf725e5..39e6cc1cac07 100644
--- a/crates/puffin-cli/tests/snapshots/pip_compile__compile_constraints_txt.snap
+++ b/crates/puffin-cli/tests/snapshots/pip_compile__compile_constraints_txt.snap
@@ -8,9 +8,9 @@ info:
     - "--constraint"
     - constraints.txt
     - "--cache-dir"
-    - /var/folders/nt/6gf2v7_s3k13zq_t3944rwz40000gn/T/.tmpvjdHOb
+    - /tmp/.tmp9F1Ljq
   env:
-    VIRTUAL_ENV: /var/folders/nt/6gf2v7_s3k13zq_t3944rwz40000gn/T/.tmpSAaWi3/.venv
+    VIRTUAL_ENV: /tmp/.tmpNJjhiS/.venv
 ---
 success: true
 exit_code: 0
@@ -22,7 +22,9 @@ asgiref==3.7.2
 django==5.0b1
 sqlparse==0.4.3
     # via django
+typing-extensions==4.8.0
+    # via asgiref
 
 ----- stderr -----
-Resolved 3 packages in [TIME]
+Resolved 4 packages in [TIME]
 
diff --git a/crates/puffin-cli/tests/snapshots/pip_compile__compile_pyproject_toml.snap b/crates/puffin-cli/tests/snapshots/pip_compile__compile_pyproject_toml.snap
index 1ace0bbb35f3..9760080af339 100644
--- a/crates/puffin-cli/tests/snapshots/pip_compile__compile_pyproject_toml.snap
+++ b/crates/puffin-cli/tests/snapshots/pip_compile__compile_pyproject_toml.snap
@@ -6,9 +6,9 @@ info:
     - pip-compile
     - pyproject.toml
     - "--cache-dir"
-    - /var/folders/nt/6gf2v7_s3k13zq_t3944rwz40000gn/T/.tmpOOTFwj
+    - /tmp/.tmphqsdmA
   env:
-    VIRTUAL_ENV: /var/folders/nt/6gf2v7_s3k13zq_t3944rwz40000gn/T/.tmpU0VXyY/.venv
+    VIRTUAL_ENV: /tmp/.tmpvlroQ4/.venv
 ---
 success: true
 exit_code: 0
@@ -20,7 +20,9 @@ asgiref==3.7.2
 django==5.0b1
 sqlparse==0.4.4
     # via django
+typing-extensions==4.8.0
+    # via asgiref
 
 ----- stderr -----
-Resolved 3 packages in [TIME]
+Resolved 4 packages in [TIME]
 
diff --git a/crates/puffin-cli/tests/snapshots/pip_compile__compile_pyproject_toml_all_extras.snap b/crates/puffin-cli/tests/snapshots/pip_compile__compile_pyproject_toml_all_extras.snap
index 2e65eb521d31..273970671e74 100644
--- a/crates/puffin-cli/tests/snapshots/pip_compile__compile_pyproject_toml_all_extras.snap
+++ b/crates/puffin-cli/tests/snapshots/pip_compile__compile_pyproject_toml_all_extras.snap
@@ -7,9 +7,9 @@ info:
     - pyproject.toml
     - "--all-extras"
     - "--cache-dir"
-    - /var/folders/nt/6gf2v7_s3k13zq_t3944rwz40000gn/T/.tmpFzJKRe
+    - /tmp/.tmpLq97XV
   env:
-    VIRTUAL_ENV: /var/folders/nt/6gf2v7_s3k13zq_t3944rwz40000gn/T/.tmpdadcmu/.venv
+    VIRTUAL_ENV: /tmp/.tmpj8K855/.venv
 ---
 success: true
 exit_code: 0
@@ -23,6 +23,8 @@ asgiref==3.7.2
 certifi==2023.7.22
     # via httpcore
 django==5.0b1
+exceptiongroup==1.1.3
+    # via anyio
 h11==0.14.0
     # via httpcore
 httpcore==0.18.0
@@ -34,7 +36,9 @@ sniffio==1.3.0
     #   httpcore
 sqlparse==0.4.4
     # via django
+typing-extensions==4.8.0
+    # via asgiref
 
 ----- stderr -----
-Resolved 9 packages in [TIME]
+Resolved 11 packages in [TIME]
 
diff --git a/crates/puffin-cli/tests/snapshots/pip_compile__compile_pyproject_toml_extra.snap b/crates/puffin-cli/tests/snapshots/pip_compile__compile_pyproject_toml_extra.snap
index 78e32bbacef9..73f1e2c7710d 100644
--- a/crates/puffin-cli/tests/snapshots/pip_compile__compile_pyproject_toml_extra.snap
+++ b/crates/puffin-cli/tests/snapshots/pip_compile__compile_pyproject_toml_extra.snap
@@ -8,9 +8,9 @@ info:
     - "--extra"
     - foo
     - "--cache-dir"
-    - /var/folders/bc/qlsk3t6x7c9fhhbvvcg68k9c0000gp/T/.tmpAYEAdM
+    - /tmp/.tmpvkwe04
   env:
-    VIRTUAL_ENV: /var/folders/bc/qlsk3t6x7c9fhhbvvcg68k9c0000gp/T/.tmp1xuOcV/.venv
+    VIRTUAL_ENV: /tmp/.tmpMFDom0/.venv
 ---
 success: true
 exit_code: 0
@@ -22,7 +22,9 @@ asgiref==3.7.2
 django==5.0b1
 sqlparse==0.4.4
     # via django
+typing-extensions==4.8.0
+    # via asgiref
 
 ----- stderr -----
-Resolved 3 packages in [TIME]
+Resolved 4 packages in [TIME]
 
diff --git a/crates/puffin-cli/tests/snapshots/pip_compile__compile_pyproject_toml_extra_name_normalization.snap b/crates/puffin-cli/tests/snapshots/pip_compile__compile_pyproject_toml_extra_name_normalization.snap
index 5eac4f49f1de..dae69a364c97 100644
--- a/crates/puffin-cli/tests/snapshots/pip_compile__compile_pyproject_toml_extra_name_normalization.snap
+++ b/crates/puffin-cli/tests/snapshots/pip_compile__compile_pyproject_toml_extra_name_normalization.snap
@@ -8,9 +8,9 @@ info:
     - "--extra"
     - FRiENDlY-...-_-BARd
     - "--cache-dir"
-    - /var/folders/bc/qlsk3t6x7c9fhhbvvcg68k9c0000gp/T/.tmpFyLXQn
+    - /tmp/.tmpVf4Xxi
   env:
-    VIRTUAL_ENV: /var/folders/bc/qlsk3t6x7c9fhhbvvcg68k9c0000gp/T/.tmpxfZatv/.venv
+    VIRTUAL_ENV: /tmp/.tmpM4Yfd8/.venv
 ---
 success: true
 exit_code: 0
@@ -22,7 +22,9 @@ asgiref==3.7.2
 django==5.0b1
 sqlparse==0.4.4
     # via django
+typing-extensions==4.8.0
+    # via asgiref
 
 ----- stderr -----
-Resolved 3 packages in [TIME]
+Resolved 4 packages in [TIME]
 
diff --git a/crates/puffin-cli/tests/snapshots/pip_compile__compile_python_37.snap b/crates/puffin-cli/tests/snapshots/pip_compile__compile_python_37.snap
index ec4e94eb422b..288ba44826d0 100644
--- a/crates/puffin-cli/tests/snapshots/pip_compile__compile_python_37.snap
+++ b/crates/puffin-cli/tests/snapshots/pip_compile__compile_python_37.snap
@@ -8,38 +8,16 @@ info:
     - "--python-version"
     - py37
     - "--cache-dir"
-    - /var/folders/nt/6gf2v7_s3k13zq_t3944rwz40000gn/T/.tmpzwzUVe
+    - /tmp/.tmpHz7Dc2
   env:
-    VIRTUAL_ENV: /var/folders/nt/6gf2v7_s3k13zq_t3944rwz40000gn/T/.tmpqFv4YL/.venv
+    VIRTUAL_ENV: /tmp/.tmpoMjDJT/.venv
 ---
-success: true
-exit_code: 0
+success: false
+exit_code: 1
 ----- stdout -----
-# This file was autogenerated by Puffin v0.0.1 via the following command:
-#    [BIN_PATH] pip-compile requirements.in --python-version py37 --cache-dir [CACHE_DIR]
-black==23.10.1
-click==8.1.7
-    # via black
-importlib-metadata==6.8.0
-    # via click
-mypy-extensions==1.0.0
-    # via black
-packaging==23.2
-    # via black
-pathspec==0.11.2
-    # via black
-platformdirs==4.0.0
-    # via black
-tomli==2.0.1
-    # via black
-typing-extensions==4.8.0
-    # via
-    #   black
-    #   importlib-metadata
-    #   platformdirs
-zipp==3.17.0
-    # via importlib-metadata
 
 ----- stderr -----
-Resolved 10 packages in [TIME]
+  × No solution found when resolving dependencies:
+  ╰─▶ Because there is no version of black available matching ==23.10.1 and
+      root depends on black==23.10.1, version solving failed.
 
diff --git a/crates/puffin-cli/tests/snapshots/pip_compile__compile_requirements_in.snap b/crates/puffin-cli/tests/snapshots/pip_compile__compile_requirements_in.snap
index 04474bfc932c..15ee38575163 100644
--- a/crates/puffin-cli/tests/snapshots/pip_compile__compile_requirements_in.snap
+++ b/crates/puffin-cli/tests/snapshots/pip_compile__compile_requirements_in.snap
@@ -6,9 +6,9 @@ info:
     - pip-compile
     - requirements.in
     - "--cache-dir"
-    - /var/folders/nt/6gf2v7_s3k13zq_t3944rwz40000gn/T/.tmpxF1zFY
+    - /tmp/.tmpNz0KIo
   env:
-    VIRTUAL_ENV: /var/folders/nt/6gf2v7_s3k13zq_t3944rwz40000gn/T/.tmp33QZdv/.venv
+    VIRTUAL_ENV: /tmp/.tmpyQ2rTA/.venv
 ---
 success: true
 exit_code: 0
@@ -20,7 +20,9 @@ asgiref==3.7.2
 django==5.0b1
 sqlparse==0.4.4
     # via django
+typing-extensions==4.8.0
+    # via asgiref
 
 ----- stderr -----
-Resolved 3 packages in [TIME]
+Resolved 4 packages in [TIME]
 
diff --git a/crates/puffin-cli/tests/snapshots/pip_sync__install_numpy_py37.snap b/crates/puffin-cli/tests/snapshots/pip_sync__install_numpy_py38.snap
similarity index 72%
rename from crates/puffin-cli/tests/snapshots/pip_sync__install_numpy_py37.snap
rename to crates/puffin-cli/tests/snapshots/pip_sync__install_numpy_py38.snap
index fbcec7ef732a..a7d0072a3f63 100644
--- a/crates/puffin-cli/tests/snapshots/pip_sync__install_numpy_py37.snap
+++ b/crates/puffin-cli/tests/snapshots/pip_sync__install_numpy_py38.snap
@@ -6,9 +6,9 @@ info:
     - pip-sync
     - requirements.txt
     - "--cache-dir"
-    - /tmp/.tmpQ4q9dh
+    - /tmp/.tmpL9E9fl
   env:
-    VIRTUAL_ENV: /tmp/.tmp6vLqVn/.venv
+    VIRTUAL_ENV: /tmp/.tmp0yDHj5/.venv
 ---
 success: true
 exit_code: 0
@@ -18,8 +18,6 @@ exit_code: 0
 Resolved 1 package in [TIME]
 Downloaded 1 package in [TIME]
 Unzipped 1 package in [TIME]
-Uninstalled 1 package in [TIME]
 Installed 1 package in [TIME]
- + numpy==1.21.6
- - werkzeug==2.0.0
+ + numpy==1.24.4
 
diff --git a/crates/puffin-resolver/src/finder.rs b/crates/puffin-resolver/src/finder.rs
index ab399b51ef4e..7f26d1f6f2e4 100644
--- a/crates/puffin-resolver/src/finder.rs
+++ b/crates/puffin-resolver/src/finder.rs
@@ -136,6 +136,20 @@ impl<'a> DistFinder<'a> {
     fn select(&self, requirement: &Requirement, files: Vec<File>) -> Option<Dist> {
         let mut fallback = None;
         for file in files.into_iter().rev() {
+            // Only add dists compatible with the python version.
+            // This is relevant for source dists which give no other indication of their
+            // compatibility and wheels which may be tagged `py3-none-any` but
+            // have `requires-python: ">=3.9"`
+            // TODO(konstin): https://github.com/astral-sh/puffin/issues/406
+            if !file
+                .requires_python
+                .as_ref()
+                .map_or(true, |requires_python| {
+                    requires_python.contains(self.interpreter_info.version())
+                })
+            {
+                continue;
+            }
             if let Ok(wheel) = WheelFilename::from_str(file.filename.as_str()) {
                 if !wheel.is_compatible(self.tags) {
                     continue;
@@ -146,18 +160,8 @@ impl<'a> DistFinder<'a> {
             } else if let Ok(sdist) =
                 SourceDistFilename::parse(file.filename.as_str(), &requirement.name)
             {
-                // Only add source dists compatible with the python version
-                // TODO(konstin): https://github.com/astral-sh/puffin/issues/406
-                if file
-                    .requires_python
-                    .as_ref()
-                    .map_or(true, |requires_python| {
-                        requires_python.contains(self.interpreter_info.version())
-                    })
-                {
-                    if requirement.is_satisfied_by(&sdist.version) {
-                        fallback = Some(Dist::from_registry(sdist.name, sdist.version, file));
-                    }
+                if requirement.is_satisfied_by(&sdist.version) {
+                    fallback = Some(Dist::from_registry(sdist.name, sdist.version, file));
                 }
             }
         }
diff --git a/crates/puffin-resolver/src/resolver.rs b/crates/puffin-resolver/src/resolver.rs
index 20543c577211..17aceb395d97 100644
--- a/crates/puffin-resolver/src/resolver.rs
+++ b/crates/puffin-resolver/src/resolver.rs
@@ -536,6 +536,21 @@ impl<'a, Context: BuildContext + Sync> Resolver<'a, Context> {
                     // distributions.
                     let mut version_map: VersionMap = BTreeMap::new();
                     for file in metadata.files {
+                        // Only add dists compatible with the python version.
+                        // This is relevant for source dists which give no other indication of their
+                        // compatibility and wheels which may be tagged `py3-none-any` but
+                        // have `requires-python: ">=3.9"`
+                        // TODO(konstin): https://github.com/astral-sh/puffin/issues/406
+                        if !file
+                            .requires_python
+                            .as_ref()
+                            .map_or(true, |requires_python| {
+                                requires_python
+                                    .contains(self.build_context.interpreter_info().version())
+                            })
+                        {
+                            continue;
+                        }
                         if let Ok(filename) = WheelFilename::from_str(file.filename.as_str()) {
                             if filename.is_compatible(self.tags) {
                                 let version = PubGrubVersion::from(filename.version.clone());
@@ -554,22 +569,11 @@ impl<'a, Context: BuildContext + Sync> Resolver<'a, Context> {
                         } else if let Ok(filename) =
                             SourceDistFilename::parse(file.filename.as_str(), &package_name)
                         {
-                            // Only add source dists compatible with the python version
-                            // TODO(konstin): https://github.com/astral-sh/puffin/issues/406
-                            if file
-                                .requires_python
-                                .as_ref()
-                                .map_or(true, |requires_python| {
-                                    requires_python
-                                        .contains(self.build_context.interpreter_info().version())
-                                })
+                            let version = PubGrubVersion::from(filename.version.clone());
+                            if let std::collections::btree_map::Entry::Vacant(entry) =
+                                version_map.entry(version)
                             {
-                                let version = PubGrubVersion::from(filename.version.clone());
-                                if let std::collections::btree_map::Entry::Vacant(entry) =
-                                    version_map.entry(version)
-                                {
-                                    entry.insert(DistFile::from(SdistFile(file)));
-                                }
+                                entry.insert(DistFile::from(SdistFile(file)));
                             }
                         }
                     }