diff --git a/lld/ELF/AArch64ErrataFix.cpp b/lld/ELF/AArch64ErrataFix.cpp
index e2c99767fad2..2dc1a61815d1 100644
--- a/lld/ELF/AArch64ErrataFix.cpp
+++ b/lld/ELF/AArch64ErrataFix.cpp
@@ -35,12 +35,13 @@
 #include "AArch64ErrataFix.h"
 #include "Config.h"
 #include "LinkerScript.h"
-#include "lld/Common/Memory.h"
 #include "OutputSections.h"
 #include "Relocations.h"
 #include "Strings.h"
+#include "Symbols.h"
 #include "SyntheticSections.h"
 #include "Target.h"
+#include "lld/Common/Memory.h"
 
 #include "llvm/Support/Endian.h"
 #include "llvm/Support/raw_ostream.h"
diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
index d4f5c89d71e2..12466e00b46a 100644
--- a/lld/ELF/Driver.cpp
+++ b/lld/ELF/Driver.cpp
@@ -34,6 +34,7 @@
 #include "ScriptParser.h"
 #include "Strings.h"
 #include "SymbolTable.h"
+#include "Symbols.h"
 #include "SyntheticSections.h"
 #include "Target.h"
 #include "Writer.h"
diff --git a/lld/ELF/GdbIndex.cpp b/lld/ELF/GdbIndex.cpp
index e858a27bc06e..d27b57f95938 100644
--- a/lld/ELF/GdbIndex.cpp
+++ b/lld/ELF/GdbIndex.cpp
@@ -15,6 +15,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "GdbIndex.h"
+#include "Symbols.h"
 #include "lld/Common/Memory.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugPubTable.h"
 #include "llvm/Object/ELFObjectFile.h"
diff --git a/lld/ELF/ICF.cpp b/lld/ELF/ICF.cpp
index ae10d4815577..09dac60c3193 100644
--- a/lld/ELF/ICF.cpp
+++ b/lld/ELF/ICF.cpp
@@ -76,6 +76,7 @@
 #include "ICF.h"
 #include "Config.h"
 #include "SymbolTable.h"
+#include "Symbols.h"
 #include "lld/Common/Threads.h"
 #include "llvm/ADT/Hashing.h"
 #include "llvm/BinaryFormat/ELF.h"
diff --git a/lld/ELF/InputFiles.h b/lld/ELF/InputFiles.h
index 4fb86f4e109e..865e38ac7a26 100644
--- a/lld/ELF/InputFiles.h
+++ b/lld/ELF/InputFiles.h
@@ -11,8 +11,6 @@
 #define LLD_ELF_INPUT_FILES_H
 
 #include "Config.h"
-#include "InputSection.h"
-#include "Symbols.h"
 #include "lld/Common/ErrorHandler.h"
 
 #include "lld/Common/LLVM.h"
@@ -40,6 +38,7 @@ class InputFile;
 namespace lld {
 namespace elf {
 class InputFile;
+class InputSectionBase;
 }
 
 // Returns "<internal>", "foo.a(bar.o)" or "baz.o".
diff --git a/lld/ELF/InputSection.cpp b/lld/ELF/InputSection.cpp
index 5daff1259ca1..737dc13ee70a 100644
--- a/lld/ELF/InputSection.cpp
+++ b/lld/ELF/InputSection.cpp
@@ -14,6 +14,7 @@
 #include "LinkerScript.h"
 #include "OutputSections.h"
 #include "Relocations.h"
+#include "Symbols.h"
 #include "SyntheticSections.h"
 #include "Target.h"
 #include "Thunks.h"
diff --git a/lld/ELF/MapFile.cpp b/lld/ELF/MapFile.cpp
index 8bf672be6fcf..dcc829315e64 100644
--- a/lld/ELF/MapFile.cpp
+++ b/lld/ELF/MapFile.cpp
@@ -25,6 +25,7 @@
 #include "OutputSections.h"
 #include "Strings.h"
 #include "SymbolTable.h"
+#include "Symbols.h"
 #include "SyntheticSections.h"
 #include "lld/Common/Threads.h"
 #include "llvm/Support/raw_ostream.h"
diff --git a/lld/ELF/Relocations.cpp b/lld/ELF/Relocations.cpp
index 13c3a4d55088..903629a44b53 100644
--- a/lld/ELF/Relocations.cpp
+++ b/lld/ELF/Relocations.cpp
@@ -47,6 +47,7 @@
 #include "OutputSections.h"
 #include "Strings.h"
 #include "SymbolTable.h"
+#include "Symbols.h"
 #include "SyntheticSections.h"
 #include "Target.h"
 #include "Thunks.h"
diff --git a/lld/ELF/SymbolTable.h b/lld/ELF/SymbolTable.h
index c4ad637e6a58..fa7c6a8d2918 100644
--- a/lld/ELF/SymbolTable.h
+++ b/lld/ELF/SymbolTable.h
@@ -18,6 +18,8 @@
 
 namespace lld {
 namespace elf {
+class Defined;
+class SectionBase;
 
 // SymbolTable is a bucket of all known symbols, including defined,
 // undefined, or lazy symbols (the last one is symbols in archive
diff --git a/lld/ELF/SyntheticSections.cpp b/lld/ELF/SyntheticSections.cpp
index 527b7fbce1af..7a454505c384 100644
--- a/lld/ELF/SyntheticSections.cpp
+++ b/lld/ELF/SyntheticSections.cpp
@@ -22,6 +22,7 @@
 #include "OutputSections.h"
 #include "Strings.h"
 #include "SymbolTable.h"
+#include "Symbols.h"
 #include "Target.h"
 #include "Writer.h"
 #include "lld/Common/ErrorHandler.h"
diff --git a/lld/ELF/SyntheticSections.h b/lld/ELF/SyntheticSections.h
index a0fa8ca44c55..0be2a29b15cd 100644
--- a/lld/ELF/SyntheticSections.h
+++ b/lld/ELF/SyntheticSections.h
@@ -30,6 +30,7 @@
 
 namespace lld {
 namespace elf {
+class SharedSymbol;
 
 class SyntheticSection : public InputSection {
 public:
diff --git a/lld/ELF/Writer.cpp b/lld/ELF/Writer.cpp
index 4ba25241e194..8c67780f5c8a 100644
--- a/lld/ELF/Writer.cpp
+++ b/lld/ELF/Writer.cpp
@@ -17,6 +17,7 @@
 #include "Relocations.h"
 #include "Strings.h"
 #include "SymbolTable.h"
+#include "Symbols.h"
 #include "SyntheticSections.h"
 #include "Target.h"
 #include "lld/Common/Memory.h"