diff --git a/include/d3d10shader.h b/include/d3d10shader.h
index 2566d42a832..af325391a49 100644
--- a/include/d3d10shader.h
+++ b/include/d3d10shader.h
@@ -206,6 +206,11 @@ DECLARE_INTERFACE_(ID3D10ShaderReflection, IUnknown)
 };
 #undef INTERFACE
 
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 HRESULT WINAPI D3D10CompileShader(LPCSTR data, SIZE_T data_size, LPCSTR filename,
         const D3D10_SHADER_MACRO *defines, ID3D10Include *include, LPCSTR entrypoint,
         LPCSTR profile, UINT flags, ID3D10Blob **shader, ID3D10Blob **error_messages);
@@ -219,4 +224,8 @@ HRESULT WINAPI D3D10GetOutputSignatureBlob(const void *data, SIZE_T data_size, I
 HRESULT WINAPI D3D10GetInputAndOutputSignatureBlob(const void *data, SIZE_T data_size, ID3D10Blob **blob);
 HRESULT WINAPI D3D10GetShaderDebugInfo(const void *data, SIZE_T data_size, ID3D10Blob **blob);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* __WINE_D3D10SHADER_H */
diff --git a/include/dsrole.h b/include/dsrole.h
index 81ec6117222..14b5731ffe1 100644
--- a/include/dsrole.h
+++ b/include/dsrole.h
@@ -21,6 +21,10 @@
 #ifndef __WINE_DSROLE_H
 #define __WINE_DSROLE_H
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #define DSROLE_PRIMARY_DS_RUNNING           0x00000001
 #define DSROLE_PRIMARY_DS_MIXED_MODE        0x00000002
 #define DSROLE_UPGRADE_IN_PROGRESS          0x00000004
@@ -81,4 +85,8 @@ typedef struct _DSROLE_OPERATION_STATE_INFO
 VOID WINAPI DsRoleFreeMemory(IN PVOID Buffer);
 DWORD WINAPI DsRoleGetPrimaryDomainInformation(IN LPCWSTR lpServer OPTIONAL, IN DSROLE_PRIMARY_DOMAIN_INFO_LEVEL InfoLevel, OUT PBYTE *Buffer);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* __WINE_DSROLE_H */
diff --git a/include/npapi.h b/include/npapi.h
index 47aa2e37b25..b5d7c978d98 100644
--- a/include/npapi.h
+++ b/include/npapi.h
@@ -18,6 +18,10 @@
 #ifndef __WINE_NPAPI_H__
 #define __WINE_NPAPI_H__
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* capabilities */
 #define WNNC_SPEC_VERSION          0x00000001
 #define WNNC_SPEC_VERSION51        0x00050001
@@ -208,4 +212,8 @@ typedef DWORD (APIENTRY *PF_AddConnectNotify)(LPNOTIFYINFO lpNotifyInfo,
 typedef DWORD (APIENTRY *PF_CancelConnectNotify)(LPNOTIFYINFO lpNotifyInfo,
  LPNOTIFYADD lpAddInfo);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* ndef __WINE_NPAPI_H__ */
diff --git a/include/ws2ipdef.h b/include/ws2ipdef.h
index 40498c06205..ea8db3d5d4d 100644
--- a/include/ws2ipdef.h
+++ b/include/ws2ipdef.h
@@ -261,6 +261,10 @@ typedef struct WS(in_pktinfo) {
 #define WS_IN6ADDR_LOOPBACK_INIT { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1 }
 #endif /* USE_WS_PREFIX */
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 static inline BOOL WS(IN6_IS_ADDR_LOOPBACK) ( const IN6_ADDR *a )
 {
     return (BOOL)((a->s6_words[0] == 0) &&
@@ -273,4 +277,8 @@ static inline BOOL WS(IN6_IS_ADDR_LOOPBACK) ( const IN6_ADDR *a )
                   (a->s6_words[7] == 0x0100));
 }
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* __WS2IPDEF__ */