diff --git a/include/wine/server_protocol.h b/include/wine/server_protocol.h
index 9e26aa4fb76..e0b63846fa7 100644
--- a/include/wine/server_protocol.h
+++ b/include/wine/server_protocol.h
@@ -714,6 +714,7 @@ typedef struct
     unsigned int   file_size;
     unsigned int   checksum;
     cpu_type_t     cpu;
+    int            __pad;
 } pe_image_info_t;
 #define IMAGE_FLAGS_ComPlusNativeReady        0x01
 #define IMAGE_FLAGS_ComPlusILOnly             0x02
diff --git a/server/mapping.c b/server/mapping.c
index 348072456ab..8a6c4f1755f 100644
--- a/server/mapping.c
+++ b/server/mapping.c
@@ -703,6 +703,7 @@ static unsigned int get_image_params( struct mapping *mapping, file_pos_t file_s
     mapping->image.gp            = 0; /* FIXME */
     mapping->image.file_size     = file_size;
     mapping->image.loader_flags  = clr_va && clr_size;
+    mapping->image.__pad         = 0;
     if (mz_size == sizeof(mz) && !memcmp( mz.buffer, builtin_signature, sizeof(builtin_signature) ))
         mapping->image.image_flags |= IMAGE_FLAGS_WineBuiltin;
     else if (mz_size == sizeof(mz) && !memcmp( mz.buffer, fakedll_signature, sizeof(fakedll_signature) ))
diff --git a/server/protocol.def b/server/protocol.def
index 79e9802aa6b..90f26d4937a 100644
--- a/server/protocol.def
+++ b/server/protocol.def
@@ -730,6 +730,7 @@ typedef struct
     unsigned int   file_size;
     unsigned int   checksum;
     cpu_type_t     cpu;
+    int            __pad;
 } pe_image_info_t;
 #define IMAGE_FLAGS_ComPlusNativeReady        0x01
 #define IMAGE_FLAGS_ComPlusILOnly             0x02