diff --git a/.travis.yml b/.travis.yml
index 1f07d4a..4b1317a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -18,6 +18,7 @@ addons:
       - texlive
       - texlive-latex-extra
       - texlive-fonts-extra
+      - latexmk
 
 # Explicitly add doctest support as separate parts of the build matrix,
 # since these tests require additional packages that should be optional.
@@ -79,7 +80,7 @@ script:
   - if [[ "${DOCTEST}" == "1" ]]; then
       cd $TRAVIS_BUILD_DIR/doc;
       make doctest;
-      make latexpdf;
+      make latexpdf LATEXOPTS="--interaction=nonstopmode";
     fi
 
 after_success:
diff --git a/doc/Makefile b/doc/Makefile
index 1d82368..6e0b610 100644
--- a/doc/Makefile
+++ b/doc/Makefile
@@ -26,7 +26,7 @@ help:
 	@echo "  devhelp    to make HTML files and a Devhelp project"
 	@echo "  epub       to make an epub"
 	@echo "  latex      to make LaTeX files, you can set PAPER=a4 or PAPER=letter"
-	@echo "  latexpdf   to make LaTeX files and run them through pdflatex"
+	@echo "  latexpdf   to make LaTeX files and run them through latexmk"
 	@echo "  text       to make text files"
 	@echo "  man        to make manual pages"
 	@echo "  changes    to make an overview of all changed/added/deprecated items"
@@ -99,9 +99,9 @@ latex:
 
 latexpdf:
 	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
-	@echo "Running LaTeX files through pdflatex..."
+	@echo "Running LaTeX files through latexmk..."
 	$(MAKE) -C $(BUILDDIR)/latex all-pdf
-	@echo "pdflatex finished; the PDF files are in $(BUILDDIR)/latex."
+	@echo "latexmk finished; the PDF files are in $(BUILDDIR)/latex."
 
 text:
 	$(SPHINXBUILD) -b text $(ALLSPHINXOPTS) $(BUILDDIR)/text
diff --git a/doc/source/conf.py b/doc/source/conf.py
index d2f9e2c..9955133 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -66,7 +66,6 @@
     \let\footnotesize\small
     \let\footnoterule\relax
     \rule{\textwidth}{1pt}%
-    \ifsphinxpdfoutput
       \begingroup
       % These \defs are required to deal with multi-line authors; it
       % changes \\ to ', ' (comma-space), making it pass muster for
@@ -298,6 +297,11 @@
 
 # Additional stuff for the LaTeX preamble.
 latex_preamble = preamble
+# In Sphinx 1.5, this now appears as latex_elements, so we pack the
+# preamble that way, too.
+latex_elements = {
+    'preamble': preamble
+}
 
 # Documents to append as an appendix to all manuals.
 #latex_appendices = []
diff --git a/src/qinfer/test_models.py b/src/qinfer/test_models.py
index adc42e6..ef091a4 100644
--- a/src/qinfer/test_models.py
+++ b/src/qinfer/test_models.py
@@ -198,8 +198,13 @@ def score(self, outcomes, modelparams, expparams, return_L=False):
         new_eps['w_'] = 0
         new_eps['t'] = expparams
 
-        return super(SimplePrecessionModel, self).score(outcomes, modelparams, new_eps, return_L)
-           
+        q = super(SimplePrecessionModel, self).score(outcomes, modelparams, new_eps, return_L=False)
+
+        if return_L:
+            return q, self.likelihood(outcomes, modelparams, expparams)
+        else:
+            return q
+
 class CoinModel(FiniteOutcomeModel, DifferentiableModel):
     r"""
     Arguably the simplest possible model; the unknown model parameter