diff --git a/clang/docs/ClangFormatStyleOptions.rst b/clang/docs/ClangFormatStyleOptions.rst
--- a/clang/docs/ClangFormatStyleOptions.rst
+++ b/clang/docs/ClangFormatStyleOptions.rst
@@ -935,6 +935,28 @@
       extern "C" {
       int foo();
       }
+  
+      true:
+      #ifdef __cplusplus
+      extern "C" {
+      #endif
+  
+          void f(void);
+  
+      #ifdef __cplusplus
+      }
+      #endif
+      
+      false:
+      #ifdef __cplusplus
+      extern "C" {
+      #endif
+  
+      void f(void);
+  
+      #ifdef __cplusplus
+      }
+      #endif
 
   * ``bool BeforeCatch`` Wrap before ``catch``.
 
diff --git a/clang/include/clang/Format/Format.h b/clang/include/clang/Format/Format.h
--- a/clang/include/clang/Format/Format.h
+++ b/clang/include/clang/Format/Format.h
@@ -977,6 +977,29 @@
     ///   } catch () {
     ///   }
     /// \endcode
+    /// \code
+    ///  true:
+    /// #ifdef __cplusplus
+    /// extern "C" {
+    /// #endif
+    ///
+    ///     void f(void);
+    ///
+    /// #ifdef __cplusplus
+    /// }
+    /// #endif
+    ///
+    /// false:
+    /// #ifdef __cplusplus
+    /// extern "C" {
+    /// #endif
+    ///
+    ///    void f(void);
+    ///
+    /// #ifdef __cplusplus
+    /// }
+    /// #endif
+    /// \endcode
     bool BeforeCatch;
     /// Wrap before ``else``.
     /// \code
diff --git a/clang/lib/Format/UnwrappedLineParser.cpp b/clang/lib/Format/UnwrappedLineParser.cpp
--- a/clang/lib/Format/UnwrappedLineParser.cpp
+++ b/clang/lib/Format/UnwrappedLineParser.cpp
@@ -1085,9 +1085,11 @@
     if (FormatTok->Tok.is(tok::string_literal)) {
       nextToken();
       if (FormatTok->Tok.is(tok::l_brace)) {
-        if (Style.BraceWrapping.AfterExternBlock) {
+        if (Style.BraceWrapping.AfterExternBlock && Style.BraceWrapping.AfterNamespace) {
           addUnwrappedLine();
           parseBlock(/*MustBeDeclaration=*/true);
+        } else if (Style.BraceWrapping.AfterExternBlock && Style.BraceWrapping.AfterNamespace == false) {
+          parseBlock(/*MustBeDeclaration=*/false);
         } else {
           parseBlock(/*MustBeDeclaration=*/true, /*AddLevel=*/false);
         }