diff --git a/lib/Analysis/CocoaConventions.cpp b/lib/Analysis/CocoaConventions.cpp
index 7e9e38f..ce973af 100644
--- a/lib/Analysis/CocoaConventions.cpp
+++ b/lib/Analysis/CocoaConventions.cpp
@@ -17,6 +17,8 @@
 #include "clang/AST/DeclObjC.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/ErrorHandling.h"
+#include <cctype>
+
 using namespace clang;
 using namespace ento;
 
diff --git a/lib/Basic/Diagnostic.cpp b/lib/Basic/Diagnostic.cpp
index cfc07b8..60feb75 100644
--- a/lib/Basic/Diagnostic.cpp
+++ b/lib/Basic/Diagnostic.cpp
@@ -17,6 +17,7 @@
 #include "llvm/ADT/SmallString.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/CrashRecoveryContext.h"
+#include <cctype>
 
 using namespace clang;
 
diff --git a/lib/Basic/IdentifierTable.cpp b/lib/Basic/IdentifierTable.cpp
index 92cc179..4869ae1 100644
--- a/lib/Basic/IdentifierTable.cpp
+++ b/lib/Basic/IdentifierTable.cpp
@@ -20,6 +20,7 @@
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/ErrorHandling.h"
+#include <cctype>
 #include <cstdio>
 
 using namespace clang;
diff --git a/lib/Frontend/LayoutOverrideSource.cpp b/lib/Frontend/LayoutOverrideSource.cpp
index eb7865e..e023250 100644
--- a/lib/Frontend/LayoutOverrideSource.cpp
+++ b/lib/Frontend/LayoutOverrideSource.cpp
@@ -9,6 +9,7 @@
 #include "clang/Frontend/LayoutOverrideSource.h"
 #include "clang/AST/Decl.h"
 #include "llvm/Support/raw_ostream.h"
+#include <cctype>
 #include <fstream>
 #include <string>
 
diff --git a/lib/Frontend/PrintPreprocessedOutput.cpp b/lib/Frontend/PrintPreprocessedOutput.cpp
index 7e0bc6b..5311ed5 100644
--- a/lib/Frontend/PrintPreprocessedOutput.cpp
+++ b/lib/Frontend/PrintPreprocessedOutput.cpp
@@ -26,6 +26,7 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/ErrorHandling.h"
+#include <cctype>
 #include <cstdio>
 using namespace clang;
 
diff --git a/lib/Frontend/TextDiagnostic.cpp b/lib/Frontend/TextDiagnostic.cpp
index 302621a..9bb3e1d 100644
--- a/lib/Frontend/TextDiagnostic.cpp
+++ b/lib/Frontend/TextDiagnostic.cpp
@@ -20,6 +20,7 @@
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringExtras.h"
 #include <algorithm>
+#include <cctype>
 
 using namespace clang;
 
diff --git a/lib/Frontend/VerifyDiagnosticConsumer.cpp b/lib/Frontend/VerifyDiagnosticConsumer.cpp
index 71c3f6b..a9378a1 100644
--- a/lib/Frontend/VerifyDiagnosticConsumer.cpp
+++ b/lib/Frontend/VerifyDiagnosticConsumer.cpp
@@ -20,6 +20,7 @@
 #include "llvm/ADT/SmallString.h"
 #include "llvm/Support/Regex.h"
 #include "llvm/Support/raw_ostream.h"
+#include <cctype>
 
 using namespace clang;
 typedef VerifyDiagnosticConsumer::Directive Directive;
diff --git a/lib/Lex/TokenConcatenation.cpp b/lib/Lex/TokenConcatenation.cpp
index 84a46ed..dd7ebb0 100644
--- a/lib/Lex/TokenConcatenation.cpp
+++ b/lib/Lex/TokenConcatenation.cpp
@@ -14,6 +14,7 @@
 #include "clang/Lex/TokenConcatenation.h"
 #include "clang/Lex/Preprocessor.h"
 #include "llvm/Support/ErrorHandling.h"
+#include <cctype>
 using namespace clang;
 
 
diff --git a/utils/TableGen/ClangDiagnosticsEmitter.cpp b/utils/TableGen/ClangDiagnosticsEmitter.cpp
index e503cb5..8e7f454 100644
--- a/utils/TableGen/ClangDiagnosticsEmitter.cpp
+++ b/utils/TableGen/ClangDiagnosticsEmitter.cpp
@@ -21,6 +21,7 @@
 #include "llvm/TableGen/Record.h"
 #include "llvm/TableGen/TableGenBackend.h"
 #include <algorithm>
+#include <cctype>
 #include <functional>
 #include <map>
 #include <set>