diff --git a/src/utils/config_overrides.cpp b/src/utils/config_overrides.cpp
index 920dd92..cb56133 100644
--- a/src/utils/config_overrides.cpp
+++ b/src/utils/config_overrides.cpp
@@ -1,6 +1,6 @@
 #include "config_overrides.hpp"
 
-#ifdef EMSCRIPTEN
+#ifdef __EMSCRIPTEN__
 #    include <iterator>
 
 #    include <git2/sys/config.h>
@@ -10,7 +10,7 @@
 
 void apply_config_overrides([[maybe_unused]] git_repository* repo)
 {
-#ifdef EMSCRIPTEN
+#ifdef __EMSCRIPTEN__
     // Config values to override, each in "name=value" form. core.filemode is disabled because
     // the emscripten filesystem does support executable file permissions but some JupyterLite
     // drive implementations do not.
diff --git a/src/wasm/libgit2_internals.cpp b/src/wasm/libgit2_internals.cpp
index 5953424..522c811 100644
--- a/src/wasm/libgit2_internals.cpp
+++ b/src/wasm/libgit2_internals.cpp
@@ -1,4 +1,4 @@
-#ifdef EMSCRIPTEN
+#ifdef __EMSCRIPTEN__
 
 #    include "libgit2_internals.hpp"
 
@@ -63,4 +63,4 @@ std::optional<http_service> select_service(git_smart_service_t action)
     return std::nullopt;
 }
 
-#endif  // EMSCRIPTEN
+#endif  // __EMSCRIPTEN__
diff --git a/src/wasm/libgit2_internals.hpp b/src/wasm/libgit2_internals.hpp
index 25a90ba..ec39782 100644
--- a/src/wasm/libgit2_internals.hpp
+++ b/src/wasm/libgit2_internals.hpp
@@ -1,6 +1,6 @@
 #pragma once
 
-#ifdef EMSCRIPTEN
+#ifdef __EMSCRIPTEN__
 
 #    include <optional>
 #    include <string>
@@ -63,4 +63,4 @@ std::string name_for_method(git_http_method method);
 
 std::optional<http_service> select_service(git_smart_service_t action);
 
-#endif  // EMSCRIPTEN
+#endif  // __EMSCRIPTEN__
diff --git a/src/wasm/read_buffer.cpp b/src/wasm/read_buffer.cpp
index c4a59ea..e22619d 100644
--- a/src/wasm/read_buffer.cpp
+++ b/src/wasm/read_buffer.cpp
@@ -1,4 +1,4 @@
-#ifdef EMSCRIPTEN
+#ifdef __EMSCRIPTEN__
 
 #    include "read_buffer.hpp"
 
@@ -9,4 +9,4 @@ read_buffer_t::read_buffer_t(char* buffer, size_t buffer_size, size_t* bytes_rea
 {
 }
 
-#endif  // EMSCRIPTEN
+#endif  // __EMSCRIPTEN__
diff --git a/src/wasm/read_buffer.hpp b/src/wasm/read_buffer.hpp
index e874f26..7d06573 100644
--- a/src/wasm/read_buffer.hpp
+++ b/src/wasm/read_buffer.hpp
@@ -1,6 +1,6 @@
 #pragma once
 
-#ifdef EMSCRIPTEN
+#ifdef __EMSCRIPTEN__
 
 #    include <stddef.h>
 
@@ -15,4 +15,4 @@ struct read_buffer_t
     size_t* m_bytes_read;
 };
 
-#endif  // EMSCRIPTEN
+#endif  // __EMSCRIPTEN__
diff --git a/src/wasm/response.cpp b/src/wasm/response.cpp
index af391f8..82a8395 100644
--- a/src/wasm/response.cpp
+++ b/src/wasm/response.cpp
@@ -1,4 +1,4 @@
-#ifdef EMSCRIPTEN
+#ifdef __EMSCRIPTEN__
 
 #    include "response.hpp"
 
@@ -82,4 +82,4 @@ void wasm_http_response::set_git_error(std::string_view url) const
     );
 }
 
-#endif  // EMSCRIPTEN
+#endif  // __EMSCRIPTEN__
diff --git a/src/wasm/response.hpp b/src/wasm/response.hpp
index 127b705..6a549fe 100644
--- a/src/wasm/response.hpp
+++ b/src/wasm/response.hpp
@@ -1,6 +1,6 @@
 #pragma once
 
-#ifdef EMSCRIPTEN
+#ifdef __EMSCRIPTEN__
 
 #    include <map>
 #    include <optional>
@@ -40,4 +40,4 @@ class wasm_http_response
     std::multimap<const std::string, const std::string> m_response_headers;
 };
 
-#endif  // EMSCRIPTEN
+#endif  // __EMSCRIPTEN__
diff --git a/src/wasm/scope.cpp b/src/wasm/scope.cpp
index b6dd4ea..52e49d4 100644
--- a/src/wasm/scope.cpp
+++ b/src/wasm/scope.cpp
@@ -1,12 +1,12 @@
 #include "scope.hpp"
 
-#ifdef EMSCRIPTEN
+#ifdef __EMSCRIPTEN__
 #    include "transport.hpp"
 #endif
 
 wasm_http_transport_scope::wasm_http_transport_scope()
 {
-#ifdef EMSCRIPTEN
+#ifdef __EMSCRIPTEN__
     git_transport_register("http", create_wasm_http_transport, nullptr);
     git_transport_register("https", create_wasm_http_transport, nullptr);
 #endif
@@ -14,7 +14,7 @@ wasm_http_transport_scope::wasm_http_transport_scope()
 
 wasm_http_transport_scope::~wasm_http_transport_scope()
 {
-#ifdef EMSCRIPTEN
+#ifdef __EMSCRIPTEN__
     git_transport_unregister("http");
     git_transport_unregister("https");
 #endif
diff --git a/src/wasm/scope.hpp b/src/wasm/scope.hpp
index 8eb1c8c..4cff033 100644
--- a/src/wasm/scope.hpp
+++ b/src/wasm/scope.hpp
@@ -3,7 +3,7 @@
 #include "../utils/common.hpp"
 
 // Scope object to enable/disable browser-based wasm http transport scheme for libgit2.
-// This is a no-op unless EMSCRIPTEN is defined.
+// This is a no-op unless __EMSCRIPTEN__ is defined.
 class wasm_http_transport_scope : noncopyable_nonmovable
 {
 public:
diff --git a/src/wasm/stream.cpp b/src/wasm/stream.cpp
index 67e7e09..959d2bf 100644
--- a/src/wasm/stream.cpp
+++ b/src/wasm/stream.cpp
@@ -1,4 +1,4 @@
-#ifdef EMSCRIPTEN
+#ifdef __EMSCRIPTEN__
 
 #    include "stream.hpp"
 
@@ -654,4 +654,4 @@ int wasm_http_stream_write(git_smart_subtransport_stream* s, const char* buffer,
     return write(stream, buffer, buffer_size);
 }
 
-#endif  // EMSCRIPTEN
+#endif  // __EMSCRIPTEN__
diff --git a/src/wasm/stream.hpp b/src/wasm/stream.hpp
index 712a35a..aaa1b4e 100644
--- a/src/wasm/stream.hpp
+++ b/src/wasm/stream.hpp
@@ -1,6 +1,6 @@
 #pragma once
 
-#ifdef EMSCRIPTEN
+#ifdef __EMSCRIPTEN__
 
 #    include <git2/sys/transport.h>
 
@@ -43,4 +43,4 @@ int wasm_http_stream_read_response(
 
 int wasm_http_stream_write(git_smart_subtransport_stream* s, const char* buffer, size_t buffer_size);
 
-#endif  // EMSCRIPTEN
+#endif  // __EMSCRIPTEN__
diff --git a/src/wasm/subtransport.cpp b/src/wasm/subtransport.cpp
index 609f73c..96ba8d4 100644
--- a/src/wasm/subtransport.cpp
+++ b/src/wasm/subtransport.cpp
@@ -1,4 +1,4 @@
-#ifdef EMSCRIPTEN
+#ifdef __EMSCRIPTEN__
 
 #    include "subtransport.hpp"
 
@@ -100,4 +100,4 @@ int create_wasm_http_subtransport(git_smart_subtransport** out, git_transport* o
     return 0;
 }
 
-#endif  // EMSCRIPTEN
+#endif  // __EMSCRIPTEN__
diff --git a/src/wasm/subtransport.hpp b/src/wasm/subtransport.hpp
index 6dd58df..94c1657 100644
--- a/src/wasm/subtransport.hpp
+++ b/src/wasm/subtransport.hpp
@@ -1,6 +1,6 @@
 #pragma once
 
-#ifdef EMSCRIPTEN
+#ifdef __EMSCRIPTEN__
 
 #    include <string>
 
@@ -24,4 +24,4 @@ struct wasm_http_subtransport
 // git_smart_subtransport_cb
 int create_wasm_http_subtransport(git_smart_subtransport** out, git_transport* owner, void* param);
 
-#endif  // EMSCRIPTEN
+#endif  // __EMSCRIPTEN__
diff --git a/src/wasm/transport.cpp b/src/wasm/transport.cpp
index 48f5697..e3a7f2f 100644
--- a/src/wasm/transport.cpp
+++ b/src/wasm/transport.cpp
@@ -1,4 +1,4 @@
-#ifdef EMSCRIPTEN
+#ifdef __EMSCRIPTEN__
 
 #    include "transport.hpp"
 
@@ -14,4 +14,4 @@ int create_wasm_http_transport(git_transport** out, git_remote* owner, void* par
     return git_transport_smart(out, owner, &definition);
 }
 
-#endif  // EMSCRIPTEN
+#endif  // __EMSCRIPTEN__
diff --git a/src/wasm/transport.hpp b/src/wasm/transport.hpp
index 93b3fea..33bbe3f 100644
--- a/src/wasm/transport.hpp
+++ b/src/wasm/transport.hpp
@@ -1,6 +1,6 @@
 #pragma once
 
-#ifdef EMSCRIPTEN
+#ifdef __EMSCRIPTEN__
 
 #    include <git2/sys/transport.h>
 
@@ -8,4 +8,4 @@
 // http(s) transport.
 int create_wasm_http_transport(git_transport** out, git_remote* owner, void* param);
 
-#endif  // EMSCRIPTEN
+#endif  // __EMSCRIPTEN__
diff --git a/src/wasm/utils.cpp b/src/wasm/utils.cpp
index 3027326..d81a46f 100644
--- a/src/wasm/utils.cpp
+++ b/src/wasm/utils.cpp
@@ -1,4 +1,4 @@
-#ifdef EMSCRIPTEN
+#ifdef __EMSCRIPTEN__
 
 #    include "utils.hpp"
 
@@ -77,4 +77,4 @@ bool maybe_prompt_to_download(double bytes)
     return true;
 }
 
-#endif  // EMSCRIPTEN
+#endif  // __EMSCRIPTEN__
diff --git a/src/wasm/utils.hpp b/src/wasm/utils.hpp
index ace9191..e4127e4 100644
--- a/src/wasm/utils.hpp
+++ b/src/wasm/utils.hpp
@@ -1,6 +1,6 @@
 #pragma once
 
-#ifdef EMSCRIPTEN
+#ifdef __EMSCRIPTEN__
 
 // Get wasm http request timeout in milliseconds from environment variable or default value.
 unsigned long get_request_timeout_ms();
@@ -9,4 +9,4 @@ unsigned long get_request_timeout_ms();
 // May or may not prompt the user for input depending on the size of the download.
 bool maybe_prompt_to_download(double bytes);
 
-#endif  // EMSCRIPTEN
+#endif  // __EMSCRIPTEN__