diff --git a/src/lang/io/io.cc b/src/lang/io/io.cc
index cf6e407dc..543bc5d8b 100644
--- a/src/lang/io/io.cc
+++ b/src/lang/io/io.cc
@@ -11,7 +11,7 @@
 #if defined(__linux__)
 #include <linux/fs.h>    // RENAME_EXCHANGE
 #include <sys/syscall.h> // SYS_renameat2, syscall
-#elifdef __APPLE__
+#elif defined(__APPLE__)
 #include <sys/stdio.h> // renameatx_np, RENAME_SWAP
 #endif
 #endif
@@ -94,7 +94,7 @@ auto atomic_directory_swap(const std::filesystem::path &original,
   }
 
   // Atomic swap via renameatx_np with RENAME_SWAP
-#elifdef __APPLE__
+#elif defined(__APPLE__)
   if (renameatx_np(AT_FDCWD, replacement.c_str(), AT_FDCWD, original.c_str(),
                    RENAME_SWAP) != 0) {
     throw std::filesystem::filesystem_error{
diff --git a/src/lang/preprocessor/include/sourcemeta/core/preprocessor.h b/src/lang/preprocessor/include/sourcemeta/core/preprocessor.h
index 5cc3a2347..550921249 100644
--- a/src/lang/preprocessor/include/sourcemeta/core/preprocessor.h
+++ b/src/lang/preprocessor/include/sourcemeta/core/preprocessor.h
@@ -3,7 +3,7 @@
 
 #if defined(__GNUC__) || defined(__clang__)
 #define SOURCEMETA_FORCEINLINE [[gnu::always_inline]]
-#elifdef _MSC_VER
+#elif defined(_MSC_VER)
 #define SOURCEMETA_FORCEINLINE [[msvc::forceinline]]
 #else
 #define SOURCEMETA_FORCEINLINE