diff --git a/apps/sources/models.py b/apps/sources/models.py
index 8e642b7a44..8b6ce91fe7 100644
--- a/apps/sources/models.py
+++ b/apps/sources/models.py
@@ -1,7 +1,10 @@
+from ast import literal_eval
+
 from django.db import models
 from django.utils.translation import ugettext_lazy as _
 from django.contrib.contenttypes.models import ContentType
 from django.contrib.contenttypes import generic
+from django.core.exceptions import ValidationError
 
 from documents.models import DocumentType
 from metadata.models import MetadataType
@@ -105,6 +108,27 @@ class WebForm(InteractiveBaseModel):
         verbose_name_plural = _(u'web forms')
 
 
+class ArgumentsValidator(object):
+    message = _(u'Enter a valid value.')
+    code = 'invalid'
+
+    def __init__(self, message=None, code=None):
+        if message is not None:
+            self.message = message
+        if code is not None:
+            self.code = code
+
+    def __call__(self, value):
+        """
+        Validates that the input evaluates correctly.
+        """
+        value = value.strip()
+        try:
+            literal_eval(value)
+        except (ValueError, SyntaxError):
+            raise ValidationError(self.message, code=self.code)
+
+
 class SourceTransformation(models.Model):
     """
     Model that stores the transformation and transformation arguments
@@ -115,7 +139,7 @@ class SourceTransformation(models.Model):
     content_object = generic.GenericForeignKey('content_type', 'object_id')
     order = models.PositiveIntegerField(default=0, blank=True, null=True, verbose_name=_(u'order'), db_index=True)
     transformation = models.CharField(choices=get_available_transformations_choices(), max_length=128, verbose_name=_(u'transformation'))
-    arguments = models.TextField(blank=True, null=True, verbose_name=_(u'arguments'), help_text=_(u'Use dictionaries to indentify arguments, example: %s') % u'{\'degrees\':90}')
+    arguments = models.TextField(blank=True, null=True, verbose_name=_(u'arguments'), help_text=_(u'Use dictionaries to indentify arguments, example: %s') % u'{\'degrees\':90}', validators=[ArgumentsValidator()])
 
     objects = SourceTransformationManager()
 
diff --git a/apps/sources/views.py b/apps/sources/views.py
index 87cd2847b2..55ceb83a45 100644
--- a/apps/sources/views.py
+++ b/apps/sources/views.py
@@ -534,17 +534,11 @@ def setup_source_transformation_edit(request, transformation_id):
         form = SourceTransformationForm(instance=source_transformation, data=request.POST)
         if form.is_valid():
             try:
-                # Test the validity of the argument field
-                eval(form.cleaned_data['arguments'], {})
-            except:
-                messages.error(request, _(u'Source transformation argument error.'))
-            else:
-                try:
-                    form.save()
-                    messages.success(request, _(u'Source transformation edited successfully'))
-                    return HttpResponseRedirect(next)
-                except Exception, e:
-                    messages.error(request, _(u'Error editing source transformation; %s') % e)
+                form.save()
+                messages.success(request, _(u'Source transformation edited successfully'))
+                return HttpResponseRedirect(next)
+            except Exception, e:
+                messages.error(request, _(u'Error editing source transformation; %s') % e)
     else:
         form = SourceTransformationForm(instance=source_transformation)
 
@@ -612,19 +606,13 @@ def setup_source_transformation_create(request, source_type, source_id):
         form = SourceTransformationForm_create(request.POST)
         if form.is_valid():
             try:
-                # Test the validity of the argument field
-                eval(form.cleaned_data['arguments'], {})
-            except:
-                messages.error(request, _(u'Source transformation argument error.'))
-            else:            
-                try:
-                    source_tranformation = form.save(commit=False)
-                    source_tranformation.content_object = source
-                    source_tranformation.save()
-                    messages.success(request, _(u'Source transformation created successfully'))
-                    return HttpResponseRedirect(redirect_view)
-                except Exception, e:
-                    messages.error(request, _(u'Error creating source transformation; %s') % e)
+                source_tranformation = form.save(commit=False)
+                source_tranformation.content_object = source
+                source_tranformation.save()
+                messages.success(request, _(u'Source transformation created successfully'))
+                return HttpResponseRedirect(redirect_view)
+            except Exception, e:
+                messages.error(request, _(u'Error creating source transformation; %s') % e)
     else:
         form = SourceTransformationForm_create()