diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,7 @@
 # Changelog for som
 
+
+10.1.5 Bug fix in SGM3.
 10.1.4 Modified SGM3 to work with limited range floating point types.
 10.1.3 Added SGM3.
 10.1.2 Fixed a warning.
diff --git a/som.cabal b/som.cabal
--- a/som.cabal
+++ b/som.cabal
@@ -2,10 +2,10 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 1bf49fbb93fa296979cf7d70de8ae9502be4b03a10627c6d7d158c97eafae269
+-- hash: ed692aa37706e47ed881b4ea21769be3add5357c26ac89e9d5408c65a03158c2
 
 name:           som
-version:        10.1.4
+version:        10.1.5
 synopsis:       Self-Organising Maps
 description:    Please see the README on GitHub at <https://github.com/mhwombat/som#readme>
 category:       Math
diff --git a/src/Data/Datamining/Clustering/SGM3Internal.hs b/src/Data/Datamining/Clustering/SGM3Internal.hs
--- a/src/Data/Datamining/Clustering/SGM3Internal.hs
+++ b/src/Data/Datamining/Clustering/SGM3Internal.hs
@@ -294,9 +294,9 @@
   :: (Num t, Ord t, Fractional x, Real x, Num x, Ord x, Enum k, Ord k)
     => SGM t x k p -> p -> (k, x, M.Map k (p, x), SGM t x k p)
 trainAndClassify s p
+  | size s == capacity s      = (bmu, bmuDiff, report, s2)
   | size s < 2               = addModelTrainAndClassify s p
-  | bmuDiff > diffThreshold
-       && size s < capacity s = addModelTrainAndClassify s p
+  | bmuDiff > diffThreshold  = addModelTrainAndClassify s p
   | bmuDiff > cutoff         = (bmu4, bmuDiff, report4, s4)
   | otherwise                = (bmu, bmuDiff, report, s2)
   where diffThreshold = meanModelDiff s
diff --git a/test/Data/Datamining/Clustering/SGM3QC.hs b/test/Data/Datamining/Clustering/SGM3QC.hs
--- a/test/Data/Datamining/Clustering/SGM3QC.hs
+++ b/test/Data/Datamining/Clustering/SGM3QC.hs
@@ -133,8 +133,7 @@
 prop_classify_never_causes_error_unless_som_empty
   :: TestSGM -> Double -> Property
 prop_classify_never_causes_error_unless_som_empty (TestSGM s _) p
-  = not (isEmpty s) ==> property $ deepseq x True
-  where x = classify s p
+  = not (isEmpty s) ==> property $ deepseq (classify s p) True
 
 prop_trainNode_reduces_diff :: TestSGM -> Double -> Property
 prop_trainNode_reduces_diff (TestSGM s _) x = not (isEmpty s) ==>
@@ -154,6 +153,10 @@
 
 -- TODO prop: map will never exceed capacity
 
+prop_train_never_causes_error :: TestSGM -> Double -> Property
+prop_train_never_causes_error (TestSGM s _) p
+  = property $ deepseq (train s p) True
+
 prop_train_only_modifies_one_model
   :: TestSGM -> Double -> Property
 prop_train_only_modifies_one_model (TestSGM s _) p
@@ -204,6 +207,7 @@
         sStable3 = trainBatch sStable2 ps
         (k2, _, _) = classify sStable3 (head ps)
 
+
 test :: Test
 test = testGroup "QuickCheck Data.Datamining.Clustering.SGM2"
   [
@@ -223,6 +227,8 @@
       prop_trainNode_reduces_diff,
     testProperty "prop_training_reduces_diff"
       prop_training_reduces_diff,
+    testProperty "prop_train_never_causes_error"
+      prop_train_never_causes_error,
     testProperty "prop_train_only_modifies_one_model"
       prop_train_only_modifies_one_model,
     testProperty "prop_train_increments_counter"