diff --git a/src/mathed/InsetMath.h b/src/mathed/InsetMath.h
index 32f265950c..421cd162b9 100644
--- a/src/mathed/InsetMath.h
+++ b/src/mathed/InsetMath.h
@@ -102,7 +102,7 @@ typedef void const * uid_type;
 class InsetMath : public Inset {
 public:
 	///
-	InsetMath(Buffer * buf = 0) : Inset(buf) {}
+	explicit InsetMath(Buffer * buf = 0) : Inset(buf) {}
 	/// identification as math inset
 	InsetMath * asInsetMath() { return this; }
 	/// identification as math inset
diff --git a/src/mathed/InsetMathBox.h b/src/mathed/InsetMathBox.h
index af166c19c7..e07fed9c48 100644
--- a/src/mathed/InsetMathBox.h
+++ b/src/mathed/InsetMathBox.h
@@ -54,7 +54,7 @@ private:
 class InsetMathFBox : public InsetMathNest {
 public:
 	///
-	InsetMathFBox(Buffer * buf);
+	explicit InsetMathFBox(Buffer * buf);
 	///
 	mode_type currentMode() const { return TEXT_MODE; }
 	///
@@ -116,7 +116,7 @@ private:
 class InsetMathBoxed : public InsetMathNest {
 public:
 	///
-	InsetMathBoxed(Buffer * buf);
+	explicit InsetMathBoxed(Buffer * buf);
 	///
 	marker_type marker(BufferView const *) const { return NO_MARKER; }
 	///
diff --git a/src/mathed/InsetMathBrace.h b/src/mathed/InsetMathBrace.h
index 82393e97fc..4a9efa716a 100644
--- a/src/mathed/InsetMathBrace.h
+++ b/src/mathed/InsetMathBrace.h
@@ -22,9 +22,9 @@ namespace lyx {
 class InsetMathBrace : public InsetMathNest {
 public:
 	///
-	InsetMathBrace(Buffer * buf);
+	explicit InsetMathBrace(Buffer * buf);
 	///
-	InsetMathBrace(MathData const & ar);
+	explicit InsetMathBrace(MathData const & ar);
 	/// identifies brace insets
 	InsetMathBrace * asBraceInset() { return this; }
 	/// identifies brace insets
diff --git a/src/mathed/InsetMathComment.h b/src/mathed/InsetMathComment.h
index 8cfe1368d7..10b244613f 100644
--- a/src/mathed/InsetMathComment.h
+++ b/src/mathed/InsetMathComment.h
@@ -23,11 +23,11 @@ class latexkeys;
 class InsetMathComment : public InsetMathNest {
 public:
 	///
-	InsetMathComment(Buffer * buf);
+	explicit InsetMathComment(Buffer * buf);
 	///
-	InsetMathComment(MathData const & ar);
+	explicit InsetMathComment(MathData const & ar);
 	///
-	explicit InsetMathComment(Buffer * buf, docstring const &);
+	InsetMathComment(Buffer * buf, docstring const &);
 	///
 	void metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
diff --git a/src/mathed/InsetMathDiagram.h b/src/mathed/InsetMathDiagram.h
index 732cd4ee1b..c7928ef576 100644
--- a/src/mathed/InsetMathDiagram.h
+++ b/src/mathed/InsetMathDiagram.h
@@ -22,7 +22,7 @@ namespace lyx {
 class InsetMathDiagram : public InsetMathGrid {
 public:
 	///
-	InsetMathDiagram(Buffer * buf);
+	explicit InsetMathDiagram(Buffer * buf);
 	///
 	void metrics(MetricsInfo &, Dimension &) const;
 	///
diff --git a/src/mathed/InsetMathDiff.h b/src/mathed/InsetMathDiff.h
index 063e5214cf..f0d16f12bb 100644
--- a/src/mathed/InsetMathDiff.h
+++ b/src/mathed/InsetMathDiff.h
@@ -24,7 +24,7 @@ namespace lyx {
 class InsetMathDiff : public InsetMathNest {
 public:
 	///
-	InsetMathDiff(Buffer * buf);
+	explicit InsetMathDiff(Buffer * buf);
 	///
 	void addDer(MathData const & der);
 	///
diff --git a/src/mathed/InsetMathEnsureMath.h b/src/mathed/InsetMathEnsureMath.h
index 41c3ad654a..45dfa2ba9a 100644
--- a/src/mathed/InsetMathEnsureMath.h
+++ b/src/mathed/InsetMathEnsureMath.h
@@ -22,7 +22,7 @@ namespace lyx {
 /// Inset for ensuring math mode
 class InsetMathEnsureMath : public InsetMathNest {
 public:
-	InsetMathEnsureMath(Buffer * buf);
+	explicit InsetMathEnsureMath(Buffer * buf);
 	///
 	mode_type currentMode() const { return MATH_MODE; }
 	///
diff --git a/src/mathed/InsetMathGrid.h b/src/mathed/InsetMathGrid.h
index a61439cfcd..b6d8044057 100644
--- a/src/mathed/InsetMathGrid.h
+++ b/src/mathed/InsetMathGrid.h
@@ -96,7 +96,7 @@ public:
 
 public:
 	/// sets nrows and ncols to 1, vertical alingment to 'c'
-	InsetMathGrid(Buffer * buf);
+	explicit InsetMathGrid(Buffer * buf);
 	/// Note: columns first!
 	InsetMathGrid(Buffer * buf, col_type m, row_type n);
 	///
diff --git a/src/mathed/InsetMathHull.h b/src/mathed/InsetMathHull.h
index a6fc8c9d64..c801a4f936 100644
--- a/src/mathed/InsetMathHull.h
+++ b/src/mathed/InsetMathHull.h
@@ -41,7 +41,7 @@ public:
 		NOTAG
 	};
 	///
-	InsetMathHull(Buffer * buf);
+	explicit InsetMathHull(Buffer * buf);
 	///
 	InsetMathHull(Buffer * buf, HullType type);
 	///
diff --git a/src/mathed/InsetMathLefteqn.h b/src/mathed/InsetMathLefteqn.h
index 1adb0bd400..0ad64af111 100644
--- a/src/mathed/InsetMathLefteqn.h
+++ b/src/mathed/InsetMathLefteqn.h
@@ -23,7 +23,7 @@ namespace lyx {
 class InsetMathLefteqn : public InsetMathNest {
 public:
 	///
-	InsetMathLefteqn(Buffer * buf);
+	explicit InsetMathLefteqn(Buffer * buf);
 	///
 	docstring name() const;
 	///
diff --git a/src/mathed/InsetMathMacroArgument.h b/src/mathed/InsetMathMacroArgument.h
index 178c89818d..fe42f2be36 100644
--- a/src/mathed/InsetMathMacroArgument.h
+++ b/src/mathed/InsetMathMacroArgument.h
@@ -24,7 +24,7 @@ namespace lyx {
 // A # that failed to parse
 class InsetMathHash : public InsetMath {
 public:
-	InsetMathHash(docstring const & str = docstring()) : str_('#' + str) {};
+	explicit InsetMathHash(docstring const & str = docstring()) : str_('#' + str) {};
 	///
 	void metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
diff --git a/src/mathed/InsetMathMacroTemplate.cpp b/src/mathed/InsetMathMacroTemplate.cpp
index c300b2c2f2..dd9bec9acc 100644
--- a/src/mathed/InsetMathMacroTemplate.cpp
+++ b/src/mathed/InsetMathMacroTemplate.cpp
@@ -250,7 +250,7 @@ void InsetDisplayLabelBox::draw(PainterInfo & pi, int x, int y) const
 class InsetMathWrapper : public InsetMath {
 public:
 	///
-	InsetMathWrapper(MathData const * value) : value_(value) {}
+	explicit InsetMathWrapper(MathData const * value) : value_(value) {}
 	///
 	void metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
@@ -755,7 +755,7 @@ class OptionalsMacroInstanceFix
 {
 public:
 	///
-	OptionalsMacroInstanceFix(int optionals) : optionals_(optionals) {}
+	explicit OptionalsMacroInstanceFix(int optionals) : optionals_(optionals) {}
 	///
 	void operator()(InsetMathMacro * macro)
 	{
diff --git a/src/mathed/InsetMathMacroTemplate.h b/src/mathed/InsetMathMacroTemplate.h
index ddcfe4df78..978aa64ed7 100644
--- a/src/mathed/InsetMathMacroTemplate.h
+++ b/src/mathed/InsetMathMacroTemplate.h
@@ -27,7 +27,7 @@ class XHTMLStream;
 class InsetMathMacroTemplate : public InsetMathNest {
 public:
 	///
-	InsetMathMacroTemplate(Buffer * buf);
+	explicit InsetMathMacroTemplate(Buffer * buf);
 	///
 	InsetMathMacroTemplate(Buffer * buf, docstring const & name, int nargs,
 		int optional, MacroType type,
diff --git a/src/mathed/InsetMathOverset.h b/src/mathed/InsetMathOverset.h
index 213c96f5b3..d7b8353922 100644
--- a/src/mathed/InsetMathOverset.h
+++ b/src/mathed/InsetMathOverset.h
@@ -22,7 +22,7 @@ namespace lyx {
 class InsetMathOverset : public InsetMathFracBase {
 public:
 	///
-	InsetMathOverset(Buffer * buf) : InsetMathFracBase(buf) {}
+	explicit InsetMathOverset(Buffer * buf) : InsetMathFracBase(buf) {}
 	///
 	void metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
diff --git a/src/mathed/InsetMathPar.h b/src/mathed/InsetMathPar.h
index 0a178f4396..5aadfa8b3a 100644
--- a/src/mathed/InsetMathPar.h
+++ b/src/mathed/InsetMathPar.h
@@ -21,7 +21,7 @@ namespace lyx {
 class InsetMathPar : public InsetMathHull {
 public:
 	///
-	InsetMathPar(Buffer * buf) : InsetMathHull(buf) {}
+	explicit InsetMathPar(Buffer * buf) : InsetMathHull(buf) {}
 	///
 	InsetMathPar(Buffer * buf, MathData const & ar);
 	///
diff --git a/src/mathed/InsetMathRef.h b/src/mathed/InsetMathRef.h
index d1046d9aba..204e9c4746 100644
--- a/src/mathed/InsetMathRef.h
+++ b/src/mathed/InsetMathRef.h
@@ -23,7 +23,7 @@ class Buffer;
 class InsetMathRef : public InsetMathCommand {
 public:
 	///
-	InsetMathRef(Buffer * buf);
+	explicit InsetMathRef(Buffer * buf);
 	///
 	explicit InsetMathRef(Buffer * buf, docstring const & data);
 	///
diff --git a/src/mathed/InsetMathRoot.h b/src/mathed/InsetMathRoot.h
index 088be24c05..144ecdf7a6 100644
--- a/src/mathed/InsetMathRoot.h
+++ b/src/mathed/InsetMathRoot.h
@@ -23,7 +23,7 @@ namespace lyx {
 class InsetMathRoot : public InsetMathNest {
 public:
 	///
-	InsetMathRoot(Buffer * buf);
+	explicit InsetMathRoot(Buffer * buf);
 	///
 	bool idxUpDown(Cursor & cur, bool up) const;
 	///
diff --git a/src/mathed/InsetMathScript.h b/src/mathed/InsetMathScript.h
index d29ffbd50b..7d7d852fb1 100644
--- a/src/mathed/InsetMathScript.h
+++ b/src/mathed/InsetMathScript.h
@@ -25,7 +25,7 @@ namespace lyx {
 class InsetMathScript : public InsetMathNest {
 public:
 	/// create inset without scripts
-	InsetMathScript(Buffer * buf);
+	explicit InsetMathScript(Buffer * buf);
 	/// create inset with single script
 	explicit InsetMathScript(Buffer * buf, bool up);
 	/// create inset with single script and given nucleus
diff --git a/src/mathed/InsetMathSqrt.h b/src/mathed/InsetMathSqrt.h
index d2aab3282b..8a9a6fc455 100644
--- a/src/mathed/InsetMathSqrt.h
+++ b/src/mathed/InsetMathSqrt.h
@@ -23,7 +23,7 @@ namespace lyx {
 class InsetMathSqrt : public InsetMathNest {
 public:
 	///
-	InsetMathSqrt(Buffer * buf);
+	explicit InsetMathSqrt(Buffer * buf);
 	///
 	void draw(PainterInfo &, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathSubstack.h b/src/mathed/InsetMathSubstack.h
index 822b0aa453..bb3089b61a 100644
--- a/src/mathed/InsetMathSubstack.h
+++ b/src/mathed/InsetMathSubstack.h
@@ -23,7 +23,7 @@ namespace lyx {
 class InsetMathSubstack : public InsetMathGrid {
 public:
 	///
-	InsetMathSubstack(Buffer * buf);
+	explicit InsetMathSubstack(Buffer * buf);
 	///
 	void metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
diff --git a/src/mathed/InsetMathUnderset.h b/src/mathed/InsetMathUnderset.h
index 50143ae4d5..565f0d5cc4 100644
--- a/src/mathed/InsetMathUnderset.h
+++ b/src/mathed/InsetMathUnderset.h
@@ -22,7 +22,7 @@ namespace lyx {
 class InsetMathUnderset : public InsetMathFracBase {
 public:
 	///
-	InsetMathUnderset(Buffer * buf) : InsetMathFracBase(buf) {}
+	explicit InsetMathUnderset(Buffer * buf) : InsetMathFracBase(buf) {}
 	///
 	void metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
diff --git a/src/mathed/MacroTable.h b/src/mathed/MacroTable.h
index eb613cae07..d31d04b35b 100644
--- a/src/mathed/MacroTable.h
+++ b/src/mathed/MacroTable.h
@@ -39,7 +39,7 @@ enum MacroType {
 class MacroData {
 public:
 	/// Constructor to make STL containers happy
-	MacroData(Buffer * buf = 0);
+	explicit MacroData(Buffer * buf = 0);
 	/// Create lazy MacroData which only queries the macro template when needed
 	MacroData(Buffer * buf, DocIterator const & pos);
 	/// Create non-lazy MacroData which directly queries the macro template
diff --git a/src/mathed/MathCompletionList.h b/src/mathed/MathCompletionList.h
index 7d36557fcb..5131f87e1f 100644
--- a/src/mathed/MathCompletionList.h
+++ b/src/mathed/MathCompletionList.h
@@ -24,7 +24,7 @@ namespace lyx {
 class MathCompletionList : public CompletionList {
 public:
 	///
-	MathCompletionList(Cursor const & cur);
+	explicit MathCompletionList(Cursor const & cur);
 	///
 	virtual ~MathCompletionList();
 
diff --git a/src/mathed/MathData.h b/src/mathed/MathData.h
index 810223d5be..3c93421821 100644
--- a/src/mathed/MathData.h
+++ b/src/mathed/MathData.h
@@ -68,7 +68,7 @@ public:
 
 public:
 	///
-	MathData(Buffer * buf = 0) : minasc_(0), mindes_(0), slevel_(0),
+	explicit MathData(Buffer * buf = 0) : minasc_(0), mindes_(0), slevel_(0),
 				     sshift_(0), buffer_(buf) {}
 	///
 	MathData(Buffer * buf, const_iterator from, const_iterator to);
diff --git a/src/mathed/MathStream.h b/src/mathed/MathStream.h
index 7779921577..df9d61088f 100644
--- a/src/mathed/MathStream.h
+++ b/src/mathed/MathStream.h
@@ -307,7 +307,7 @@ public:
 class ETag {
 public:
 	///
-	ETag(char const * const tag) : tag_(tag) {}
+	explicit ETag(char const * const tag) : tag_(tag) {}
 	///
 	char const * const tag_;
 };