diff --git a/java/core/src/main/java/ws/epigraph/data/BooleanDatum.java b/java/core/src/main/java/ws/epigraph/data/BooleanDatum.java
index e9c81011f..40313df2f 100644
--- a/java/core/src/main/java/ws/epigraph/data/BooleanDatum.java
+++ b/java/core/src/main/java/ws/epigraph/data/BooleanDatum.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 Sumo Logic
+ * Copyright 2017 Sumo Logic
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -193,6 +193,7 @@ public static final class Raw extends BooleanDatum.Builder implements BooleanDat
 
       public Raw(@NotNull BooleanType type, @NotNull Boolean val) {
         super(type);
+        if (val == null) throw new IllegalArgumentException();
         this.val = val;
       }
 
diff --git a/java/core/src/main/java/ws/epigraph/data/IntegerDatum.java b/java/core/src/main/java/ws/epigraph/data/IntegerDatum.java
index 484cc0b69..b8593f54a 100644
--- a/java/core/src/main/java/ws/epigraph/data/IntegerDatum.java
+++ b/java/core/src/main/java/ws/epigraph/data/IntegerDatum.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 Sumo Logic
+ * Copyright 2017 Sumo Logic
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -193,6 +193,7 @@ public static final class Raw extends IntegerDatum.Builder implements IntegerDat
 
       public Raw(@NotNull IntegerType type, @NotNull Integer val) {
         super(type);
+        if (val == null) throw new IllegalArgumentException();
         this.val = val;
       }
 
diff --git a/java/core/src/main/java/ws/epigraph/data/ListDatum.java b/java/core/src/main/java/ws/epigraph/data/ListDatum.java
index f203062cd..5d87b592b 100644
--- a/java/core/src/main/java/ws/epigraph/data/ListDatum.java
+++ b/java/core/src/main/java/ws/epigraph/data/ListDatum.java
@@ -156,6 +156,7 @@ protected Impl(
           super(type);
           // TODO check types are compatible
           this.raw = raw; // TODO validate raw internals is kosher?
+          if (raw == null) throw new IllegalArgumentException();
           this.value = immValConstructor.apply(new Val.Imm.Raw.DatumVal(this));
         }
 
diff --git a/java/core/src/main/java/ws/epigraph/data/LongDatum.java b/java/core/src/main/java/ws/epigraph/data/LongDatum.java
index 69db53385..962b053ff 100644
--- a/java/core/src/main/java/ws/epigraph/data/LongDatum.java
+++ b/java/core/src/main/java/ws/epigraph/data/LongDatum.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 Sumo Logic
+ * Copyright 2017 Sumo Logic
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -193,6 +193,7 @@ public static final class Raw extends LongDatum.Builder implements LongDatum.Raw
 
       public Raw(@NotNull LongType type, @NotNull Long val) {
         super(type);
+        if (val == null) throw new IllegalArgumentException();
         this.val = val;
       }
 
diff --git a/java/core/src/main/java/ws/epigraph/data/MapDatum.java b/java/core/src/main/java/ws/epigraph/data/MapDatum.java
index d68b01d6d..fa028d2df 100644
--- a/java/core/src/main/java/ws/epigraph/data/MapDatum.java
+++ b/java/core/src/main/java/ws/epigraph/data/MapDatum.java
@@ -163,6 +163,7 @@ protected Impl(
           super(type);
           // TODO check types are compatible
           this.raw = raw; // TODO validate raw internals is kosher (i.e. contains static datums)?
+          if (raw == null) throw new IllegalArgumentException();
           this.value = immValConstructor.apply(new Val.Imm.Raw.DatumVal(this));
         }
 
diff --git a/java/core/src/main/java/ws/epigraph/data/StringDatum.java b/java/core/src/main/java/ws/epigraph/data/StringDatum.java
index 0188ec8e0..e5d8a334c 100644
--- a/java/core/src/main/java/ws/epigraph/data/StringDatum.java
+++ b/java/core/src/main/java/ws/epigraph/data/StringDatum.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 Sumo Logic
+ * Copyright 2017 Sumo Logic
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -195,6 +195,7 @@ public static final class Raw extends StringDatum.Builder
 
       public Raw(@NotNull StringType type, @NotNull String val) {
         super(type);
+        if (val == null) throw new IllegalArgumentException();
         this.val = val;
       }
 
diff --git a/java/core/src/main/java/ws/epigraph/types/StringType.java b/java/core/src/main/java/ws/epigraph/types/StringType.java
index b1a68d55f..b03818458 100644
--- a/java/core/src/main/java/ws/epigraph/types/StringType.java
+++ b/java/core/src/main/java/ws/epigraph/types/StringType.java
@@ -124,11 +124,19 @@ protected Static(
       return datumBuilderConstructor.apply(new StringDatum.Builder.Raw(this, val));
     }
 
+    public final @NotNull MyDatumBuilder createBuilder(@NotNull CharSequence val) {
+      return createBuilder(val.toString());
+    }
+
     @Override
     public final @NotNull MyImmVal createValueOfNullable(@Nullable String val) {
       return val == null ? createValue(null) : createBuilder(val).asValue().toImmutable();
     }
 
+    public final @NotNull MyImmVal createValueOfNullable(@Nullable CharSequence val) {
+      return createValueOfNullable(val == null ? null : val.toString());
+    }
+
     @Override
     public final @NotNull MyImmVal createValue(@Nullable ErrorValue errorOrNull) {
       return immValConstructor.apply(Val.Imm.Raw.create(errorOrNull));
diff --git a/java/util/src/main/java/ws/epigraph/util/WordUtil.java b/java/util/src/main/java/ws/epigraph/util/WordUtil.java
index 8e98ad643..800c046c5 100644
--- a/java/util/src/main/java/ws/epigraph/util/WordUtil.java
+++ b/java/util/src/main/java/ws/epigraph/util/WordUtil.java
@@ -37,7 +37,7 @@ public static String suggest(String mistype, Collection<String> options, String
     return toDistance.entrySet().stream()
         .filter(e -> e.getValue() >= threshold)
         .max(Map.Entry.comparingByValue())
-        .map(e -> String.format(format, e.getValue()))
+        .map(e -> String.format(format, e.getKey()))
         .orElse(noSuggestion);
   }