diff --git a/src/BufferParams.cpp b/src/BufferParams.cpp
index c98e1f9d97..55c2fa1c98 100644
--- a/src/BufferParams.cpp
+++ b/src/BufferParams.cpp
@@ -1445,9 +1445,13 @@ bool BufferParams::writeLaTeX(otexstream & os, LaTeXFeatures & features,
 	os << '{' << from_ascii(tclass.latexname()) << "}\n";
 	// end of \documentclass defs
 
-	// if we use fontspec, we have to load the AMS packages here
+	// if we use fontspec or newtxmath, we have to load the AMS packages here
 	string const ams = features.loadAMSPackages();
-	if (useNonTeXFonts && !ams.empty())
+	bool const ot1 = (font_encoding() == "default" || font_encoding() == "OT1");
+	bool const use_newtxmath =
+		theLaTeXFonts().getLaTeXFont(from_ascii(fonts_math)).getUsedPackage(
+			ot1, false, false) == "newtxmath";
+	if ((useNonTeXFonts || use_newtxmath) && !ams.empty())
 		os << from_ascii(ams);
 
 	if (useNonTeXFonts) {
diff --git a/src/LaTeXFeatures.cpp b/src/LaTeXFeatures.cpp
index d4074d6109..9292938c0f 100644
--- a/src/LaTeXFeatures.cpp
+++ b/src/LaTeXFeatures.cpp
@@ -851,10 +851,15 @@ string const LaTeXFeatures::getPackages() const
 	// The rest of these packages are somewhat more complicated
 	// than those above.
 
-	// if fontspec is used, AMS packages have to be loaded before
-	// fontspec (in BufferParams)
+	// if fontspec or newtxmath is used, AMS packages have to be loaded
+	// before fontspec (in BufferParams)
 	string const amsPackages = loadAMSPackages();
-	if (!params_.useNonTeXFonts && !amsPackages.empty())
+	bool const ot1 = (params_.font_encoding() == "default" || params_.font_encoding() == "OT1");
+	bool const use_newtxmath =
+		theLaTeXFonts().getLaTeXFont(from_ascii(params_.fonts_math)).getUsedPackage(
+			ot1, false, false) == "newtxmath";
+	
+	if (!params_.useNonTeXFonts && !use_newtxmath && !amsPackages.empty())
 		packages << amsPackages;
 
 	// fixltx2e must be loaded after amsthm, since amsthm produces an error with
@@ -863,9 +868,9 @@ string const LaTeXFeatures::getPackages() const
 	if (mustProvide("fixltx2e"))
 		packages << "\\usepackage{fixltx2e}\n";
 
-        if (mustProvide("cancel") &&
-            params_.use_package("cancel") != BufferParams::package_off)
-                packages << "\\usepackage{cancel}\n";
+	if (mustProvide("cancel") &&
+	    params_.use_package("cancel") != BufferParams::package_off)
+		packages << "\\usepackage{cancel}\n";
 	// wasysym is a simple feature, but it must be after amsmath if both
 	// are used
 	// wasysym redefines some integrals (e.g. iint) from amsmath. That
diff --git a/src/LaTeXFonts.cpp b/src/LaTeXFonts.cpp
index e37ad2e945..676179f5a5 100644
--- a/src/LaTeXFonts.cpp
+++ b/src/LaTeXFonts.cpp
@@ -193,6 +193,15 @@ docstring const LaTeXFont::getUsedFont(bool ot1, bool complete, bool nomath)
 }
 
 
+docstring const LaTeXFont::getUsedPackage(bool ot1, bool complete, bool nomath)
+{
+	docstring const usedfont = getUsedFont(ot1, complete, nomath);
+	if (usedfont.empty())
+		return docstring();
+	return theLaTeXFonts().getLaTeXFont(usedfont).package();
+}
+
+
 string const LaTeXFont::getAvailablePackage(bool dryrun)
 {
 	if (package_.empty())
diff --git a/src/LaTeXFonts.h b/src/LaTeXFonts.h
index 8c9da88e5e..a50a0770d9 100644
--- a/src/LaTeXFonts.h
+++ b/src/LaTeXFonts.h
@@ -82,6 +82,8 @@ public:
 				       int const & scale = 100);
 	/// Return the actually used font
 	docstring const getUsedFont(bool ot1, bool complete, bool nomath);
+	/// Return the actually used package
+	docstring const getUsedPackage(bool ot1, bool complete, bool nomath);
 	///
 	bool read(Lexer & lex);
 	///