diff --git a/src/fs.cpp b/src/fs.cpp
index e68c97b3caf..eef9c81de92 100644
--- a/src/fs.cpp
+++ b/src/fs.cpp
@@ -5,10 +5,12 @@
 #include <fs.h>
 
 #ifndef WIN32
+#include <cstring>
 #include <fcntl.h>
 #include <string>
 #include <sys/file.h>
 #include <sys/utsname.h>
+#include <unistd.h>
 #else
 #ifndef NOMINMAX
 #define NOMINMAX
@@ -31,7 +33,8 @@ FILE *fopen(const fs::path& p, const char *mode)
 
 #ifndef WIN32
 
-static std::string GetErrorReason() {
+static std::string GetErrorReason()
+{
     return std::strerror(errno);
 }
 
diff --git a/src/interfaces/chain.h b/src/interfaces/chain.h
index 61d7ddb9340..65695707f75 100644
--- a/src/interfaces/chain.h
+++ b/src/interfaces/chain.h
@@ -8,6 +8,7 @@
 #include <optional.h>               // For Optional and nullopt
 #include <primitives/transaction.h> // For CTransactionRef
 
+#include <functional>
 #include <memory>
 #include <stddef.h>
 #include <stdint.h>