diff --git a/src/Buffer.cpp b/src/Buffer.cpp
index dec742f334..5be6679dca 100644
--- a/src/Buffer.cpp
+++ b/src/Buffer.cpp
@@ -588,7 +588,7 @@ bool Buffer::readDocument(Lexer & lex)
 		FileName const master_file = makeAbsPath(params().master,
 			   onlyPath(absFileName()));
 		if (isLyXFilename(master_file.absFilename())) {
-			Buffer * master = checkAndLoadLyXFile(master_file);
+			Buffer * master = checkAndLoadLyXFile(master_file, true);
 			d->parent_buffer = master;
 		}
 	}
diff --git a/src/buffer_funcs.cpp b/src/buffer_funcs.cpp
index 861413dcd9..f82535bae7 100644
--- a/src/buffer_funcs.cpp
+++ b/src/buffer_funcs.cpp
@@ -57,12 +57,15 @@ namespace lyx {
 namespace Alert = frontend::Alert;
 
 
-Buffer * checkAndLoadLyXFile(FileName const & filename)
+Buffer * checkAndLoadLyXFile(FileName const & filename, bool const acceptDirty)
 {
 	// File already open?
 	Buffer * checkBuffer = theBufferList().getBuffer(filename);
 	if (checkBuffer) {
-		if (checkBuffer->isClean())
+		// sometimes (when setting the master buffer from a child)
+		// we accept a dirty buffer right away (otherwise we'd get
+		// an infinite loop (bug 5514)
+		if (checkBuffer->isClean() || acceptDirty)
 			return checkBuffer;
 		docstring const file = makeDisplayPath(filename.absFilename(), 20);
 		docstring text = bformat(_(
diff --git a/src/buffer_funcs.h b/src/buffer_funcs.h
index d34a7406c3..8e67a3fdc6 100644
--- a/src/buffer_funcs.h
+++ b/src/buffer_funcs.h
@@ -27,7 +27,8 @@ class ParIterator;
  *  \retval the newly created \c Buffer pointer if successful or 0.
  *  \retval 0 if the \c Buffer could not be created.
  */
-Buffer * checkAndLoadLyXFile(support::FileName const & filename);
+Buffer * checkAndLoadLyXFile(support::FileName const & filename,
+		bool acceptDirty = false);
 
 /** Make a new file (buffer) with name \c filename based on a template
  *  named \c templatename