diff --git a/Code/Mantid/docs/source/algorithms/ReflectometryReductionOne-v1.rst b/Code/Mantid/docs/source/algorithms/ReflectometryReductionOne-v1.rst
index 5049a19eb382d2f1683741e25364d0cdad74b814..627e6cffd4167de2f511596c6e6eff805a1be451 100644
--- a/Code/Mantid/docs/source/algorithms/ReflectometryReductionOne-v1.rst
+++ b/Code/Mantid/docs/source/algorithms/ReflectometryReductionOne-v1.rst
@@ -20,7 +20,7 @@ script.
 Workflow
 ########
 
-.. diagram:: ReflectometryReductionOne
+.. diagram:: ReflectometryReductionOne-v1_wkflw.dot
 
 Analysis Modes
 ##############
diff --git a/Code/Mantid/docs/source/algorithms/ReflectometryReductionOneAuto-v1.rst b/Code/Mantid/docs/source/algorithms/ReflectometryReductionOneAuto-v1.rst
index 30947ebe624f77321d017fc61e188207c8960210..809be7a932871e8d3a8f8ca73f0c76c1037d5b92 100644
--- a/Code/Mantid/docs/source/algorithms/ReflectometryReductionOneAuto-v1.rst
+++ b/Code/Mantid/docs/source/algorithms/ReflectometryReductionOneAuto-v1.rst
@@ -26,7 +26,7 @@ Workflow for WorkspaceGroups
 
 If a WorkspaceGroup is provided to ReflectometryReductionOneAuto, it will follow the steps shown in the diagram below to produce its output.
 
-.. diagram:: ReflectometryReductionOneAuto-Groups
+.. diagram:: ReflectometryReductionOneAuto-v1-Groups_wkflw.dot
 
 Workflow for Polarization Correction
 ####################################
@@ -34,7 +34,7 @@ Workflow for Polarization Correction
 If polarization correction is enabled, it is performed as an additional step once the main processing has completed.
 The following diagram shows how the :ref:`algm-PolarizationCorrection` algorithm is used.
 
-.. diagram:: ReflectometryReductionOneAuto-PolarizationCorrection
+.. diagram:: ReflectometryReductionOneAuto-v1-PolarizationCorrection_wkflw.dot
 
 Usage
 -----
diff --git a/Code/Mantid/docs/source/diagrams/ReflectometryReductionOne.dot b/Code/Mantid/docs/source/diagrams/ReflectometryReductionOne-v1_wkflw.dot
similarity index 100%
rename from Code/Mantid/docs/source/diagrams/ReflectometryReductionOne.dot
rename to Code/Mantid/docs/source/diagrams/ReflectometryReductionOne-v1_wkflw.dot
diff --git a/Code/Mantid/docs/source/diagrams/ReflectometryReductionOneAuto-Groups.dot b/Code/Mantid/docs/source/diagrams/ReflectometryReductionOneAuto-v1-Groups_wkflw.dot
similarity index 100%
rename from Code/Mantid/docs/source/diagrams/ReflectometryReductionOneAuto-Groups.dot
rename to Code/Mantid/docs/source/diagrams/ReflectometryReductionOneAuto-v1-Groups_wkflw.dot
diff --git a/Code/Mantid/docs/source/diagrams/ReflectometryReductionOneAuto-PolarizationCorrection.dot b/Code/Mantid/docs/source/diagrams/ReflectometryReductionOneAuto-v1-PolarizationCorrection_wkflw.dot
similarity index 100%
rename from Code/Mantid/docs/source/diagrams/ReflectometryReductionOneAuto-PolarizationCorrection.dot
rename to Code/Mantid/docs/source/diagrams/ReflectometryReductionOneAuto-v1-PolarizationCorrection_wkflw.dot
diff --git a/Code/Mantid/docs/sphinxext/mantiddoc/directives/diagram.py b/Code/Mantid/docs/sphinxext/mantiddoc/directives/diagram.py
index 3daf8b8fa06e37c5b737bc00a1310ae6b384a457..2d64928d29f5bb4ba713f00d4a6f7bc195e74244 100644
--- a/Code/Mantid/docs/sphinxext/mantiddoc/directives/diagram.py
+++ b/Code/Mantid/docs/sphinxext/mantiddoc/directives/diagram.py
@@ -68,11 +68,18 @@ class DiagramDirective(BaseDirective):
             os.makedirs(out_dir)
 
         diagram_name = self.arguments[0]
-        in_path = os.path.join(env.srcdir, "diagrams", diagram_name + ".dot")
-        out_path = os.path.join(out_dir, diagram_name + ".png")
+        if diagram_name[-4:] != ".dot":
+            raise RuntimeError("Diagrams need to be referred to by their filename, including '.dot' extension.")
+
+        in_path = os.path.join(env.srcdir, "diagrams", diagram_name)
+        out_path = os.path.join(out_dir, diagram_name[:-4] + ".png")
 
         #Generate the diagram
-        in_src = open(in_path, 'r').read()
+        try:
+            in_src = open(in_path, 'r').read()
+        except:
+            raise RuntimeError("Cannot find dot-file: '" + diagram_name + "' in '" + os.path.join(env.srcdir,"diagrams"))
+
         out_src = string.Template(in_src).substitute(STYLE)
         gviz = subprocess.Popen([dot_executable,"-Tpng","-o",out_path], stdin=subprocess.PIPE)
         gviz.communicate(input=out_src)