diff --git a/.gx/lastpubver b/.gx/lastpubver
deleted file mode 100644
index caa3a7fdfbd0210e5db7171c0c419c2b71507229..0000000000000000000000000000000000000000
--- a/.gx/lastpubver
+++ /dev/null
@@ -1 +0,0 @@
-0.1.6: QmYmZ81dU5nnmBFy5MmktXLZpt8QCWhRJd6M1uxVF6vke8
diff --git a/.travis.yml b/.travis.yml
index 4cfe98c2424d60b3a50d870dc0da5df2ee9243ba..f32dfd14c65e4434162ab18cb36ef68f3bc02ac4 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -9,11 +9,8 @@ go:
 env:
   global:
     - GOTFLAGS="-race"
-  matrix:
-    - BUILD_DEPTYPE=gx
     - BUILD_DEPTYPE=gomod
 
-
 # disable travis install
 install:
   - true
@@ -24,7 +21,6 @@ script:
 
 cache:
   directories:
-    - $GOPATH/src/gx
     - $GOPATH/pkg/mod
     - $HOME/.cache/go-build
 
diff --git a/Makefile b/Makefile
deleted file mode 100644
index 73f2841f618b54e03cb34a9c91c8a0596a829c31..0000000000000000000000000000000000000000
--- a/Makefile
+++ /dev/null
@@ -1,18 +0,0 @@
-all: deps
-gx:
-	go get github.com/whyrusleeping/gx
-	go get github.com/whyrusleeping/gx-go
-deps: gx 
-	gx --verbose install --global
-	gx-go rewrite
-test: deps
-	gx test -v -race -coverprofile=coverage.txt -covermode=atomic .
-rw:
-	gx-go rewrite
-rwundo:
-	gx-go rewrite --undo
-publish: rwundo
-	gx publish
-.PHONY: all gx deps test rw rwundo publish
-
-
diff --git a/README.md b/README.md
index 84161c5466f80944d67e446f8d947b32877f9ef5..7b1b5b2389ef60543549e62f77d421d01a118219 100644
--- a/README.md
+++ b/README.md
@@ -31,8 +31,6 @@ The package provides a `SizeSplitter` which creates chunks of equal size and it
 > go get github.com/ipfs/go-ipfs-chunker
 ```
 
-It uses [Gx](https://github.com/whyrusleeping/gx) to manage dependencies. You can use `make all` to build it with the `gx` dependencies.
-
 ## Usage
 
 ```
diff --git a/package.json b/package.json
deleted file mode 100644
index d53c0e7b79046a60c92f806c3cb0ad9a9e4e940f..0000000000000000000000000000000000000000
--- a/package.json
+++ /dev/null
@@ -1,47 +0,0 @@
-{
-  "author": "hsanjuan",
-  "bugs": {
-    "url": "https://github.com/ipfs/go-ipfs-chunker"
-  },
-  "gx": {
-    "dvcsimport": "github.com/ipfs/go-ipfs-chunker"
-  },
-  "gxDependencies": [
-    {
-      "hash": "QmbkT7eMTyXfpeyB3ZMxxcxg7XH8t6uXp49jqzz4HB7BGF",
-      "name": "go-log",
-      "version": "1.5.9"
-    },
-    {
-      "author": "whyrusleeping",
-      "hash": "QmZooytqEoUwQjv7KzH4d3xyJnyvD3AWJaCDMYt5pbCtua",
-      "name": "chunker",
-      "version": "0.0.1"
-    },
-    {
-      "author": "whyrusleeping",
-      "hash": "QmNohiVssaPw3KVLZik59DBVGTSm2dGvYT9eoXt5DQ36Yz",
-      "name": "go-ipfs-util",
-      "version": "1.2.9"
-    },
-    {
-      "author": "stebalien",
-      "hash": "QmYYLnAzR28nAQ4U5MFniLprnktu6eTFKibeNt96V21EZK",
-      "name": "go-block-format",
-      "version": "0.2.2"
-    },
-    {
-      "author": "Stebalien",
-      "hash": "QmQDvJoB6aJWN3sjr3xsgXqKCXf4jU5zdMXpDMsBkYVNqa",
-      "name": "go-buffer-pool",
-      "version": "0.1.3"
-    }
-  ],
-  "gxVersion": "0.12.1",
-  "language": "go",
-  "license": "MIT",
-  "name": "go-ipfs-chunker",
-  "releaseCmd": "git commit -a -m \"gx publish $VERSION\"",
-  "version": "0.1.6"
-}
-
diff --git a/parse.go b/parse.go
index 5d472b70928130db808659d56f1836c95e3ba041..dee830489aa71ec58d32181f0081ad3057553f71 100644
--- a/parse.go
+++ b/parse.go
@@ -8,9 +8,20 @@ import (
 	"strings"
 )
 
+const (
+	// DefaultBlockSize is the chunk size that splitters produce (or aim to).
+	DefaultBlockSize int64 = 1024 * 256
+
+	// No leaf block should contain more than 1MiB of payload data ( wrapping overhead aside )
+	// This effectively mandates the maximum chunk size
+	// See discussion at https://github.com/ipfs/go-ipfs-chunker/pull/21#discussion_r369124879 for background
+	ChunkSizeLimit int = 1048576
+)
+
 var (
 	ErrRabinMin = errors.New("rabin min must be greater than 16")
-	ErrSize     = errors.New("chunker size muster greater than 0")
+	ErrSize     = errors.New("chunker size must be greater than 0")
+	ErrSizeMax  = fmt.Errorf("chunker parameters may not exceed the maximum chunk size of %d", ChunkSizeLimit)
 )
 
 // FromString returns a Splitter depending on the given string:
@@ -28,6 +39,8 @@ func FromString(r io.Reader, chunker string) (Splitter, error) {
 			return nil, err
 		} else if size <= 0 {
 			return nil, ErrSize
+		} else if size > ChunkSizeLimit {
+			return nil, ErrSizeMax
 		}
 		return NewSizeSplitter(r, int64(size)), nil
 
@@ -51,6 +64,8 @@ func parseRabinString(r io.Reader, chunker string) (Splitter, error) {
 		size, err := strconv.Atoi(parts[1])
 		if err != nil {
 			return nil, err
+		} else if int(float32(size)*1.5) > ChunkSizeLimit { // FIXME - this will be addressed in a subsequent PR
+			return nil, ErrSizeMax
 		}
 		return NewRabin(r, uint64(size)), nil
 	case 4:
@@ -84,6 +99,14 @@ func parseRabinString(r io.Reader, chunker string) (Splitter, error) {
 			return nil, err
 		}
 
+		if min >= avg {
+			return nil, errors.New("incorrect format: rabin-min must be smaller than rabin-avg")
+		} else if avg >= max {
+			return nil, errors.New("incorrect format: rabin-avg must be smaller than rabin-max")
+		} else if max > ChunkSizeLimit {
+			return nil, ErrSizeMax
+		}
+
 		return NewRabinMinMax(r, uint64(min), uint64(avg), uint64(max)), nil
 	default:
 		return nil, errors.New("incorrect format (expected 'rabin' 'rabin-[avg]' or 'rabin-[min]-[avg]-[max]'")
diff --git a/parse_test.go b/parse_test.go
index f82aba5f2cf6e80e55039c55f6c7a7501d9f377b..237a2b439a6cc74a0a83a3b63da3affa0e9cee87 100644
--- a/parse_test.go
+++ b/parse_test.go
@@ -2,35 +2,79 @@ package chunk
 
 import (
 	"bytes"
+	"fmt"
 	"testing"
 )
 
+const (
+	testTwoThirdsOfChunkLimit = 2 * (float32(ChunkSizeLimit) / float32(3))
+)
+
 func TestParseRabin(t *testing.T) {
-	max := 1000
-	r := bytes.NewReader(randBuf(t, max))
-	chk1 := "rabin-18-25-32"
-	chk2 := "rabin-15-23-31"
-	_, err := parseRabinString(r, chk1)
+	r := bytes.NewReader(randBuf(t, 1000))
+
+	_, err := FromString(r, "rabin-18-25-32")
 	if err != nil {
 		t.Errorf(err.Error())
 	}
-	_, err = parseRabinString(r, chk2)
-	if err == ErrRabinMin {
-		t.Log("it should be ErrRabinMin here.")
+
+	_, err = FromString(r, "rabin-15-23-31")
+	if err != ErrRabinMin {
+		t.Fatalf("Expected an 'ErrRabinMin' error, got: %#v", err)
+	}
+
+	_, err = FromString(r, "rabin-20-20-21")
+	if err == nil || err.Error() != "incorrect format: rabin-min must be smaller than rabin-avg" {
+		t.Fatalf("Expected an arg-out-of-order error, got: %#v", err)
+	}
+
+	_, err = FromString(r, "rabin-19-21-21")
+	if err == nil || err.Error() != "incorrect format: rabin-avg must be smaller than rabin-max" {
+		t.Fatalf("Expected an arg-out-of-order error, got: %#v", err)
+	}
+
+	_, err = FromString(r, fmt.Sprintf("rabin-19-21-%d", ChunkSizeLimit))
+	if err != nil {
+		t.Fatalf("Expected success, got: %#v", err)
+	}
+
+	_, err = FromString(r, fmt.Sprintf("rabin-19-21-%d", 1+ChunkSizeLimit))
+	if err != ErrSizeMax {
+		t.Fatalf("Expected 'ErrSizeMax', got: %#v", err)
+	}
+
+	_, err = FromString(r, fmt.Sprintf("rabin-%.0f", testTwoThirdsOfChunkLimit))
+	if err != nil {
+		t.Fatalf("Expected success, got: %#v", err)
+	}
+
+	_, err = FromString(r, fmt.Sprintf("rabin-%.0f", 1+testTwoThirdsOfChunkLimit))
+	if err != ErrSizeMax {
+		t.Fatalf("Expected 'ErrSizeMax', got: %#v", err)
 	}
+
 }
 
 func TestParseSize(t *testing.T) {
-	max := 1000
-	r := bytes.NewReader(randBuf(t, max))
-	size1 := "size-0"
-	size2 := "size-32"
-	_, err := FromString(r, size1)
-	if err == ErrSize {
-		t.Log("it should be ErrSize here.")
-	}
-	_, err = FromString(r, size2)
-	if err == ErrSize {
-		t.Fatal(err)
+	r := bytes.NewReader(randBuf(t, 1000))
+
+	_, err := FromString(r, "size-0")
+	if err != ErrSize {
+		t.Fatalf("Expected an 'ErrSize' error, got: %#v", err)
+	}
+
+	_, err = FromString(r, "size-32")
+	if err != nil {
+		t.Fatalf("Expected success, got: %#v", err)
+	}
+
+	_, err = FromString(r, fmt.Sprintf("size-%d", ChunkSizeLimit))
+	if err != nil {
+		t.Fatalf("Expected success, got: %#v", err)
+	}
+
+	_, err = FromString(r, fmt.Sprintf("size-%d", 1+ChunkSizeLimit))
+	if err != ErrSizeMax {
+		t.Fatalf("Expected 'ErrSizeMax', got: %#v", err)
 	}
 }
diff --git a/splitting.go b/splitting.go
index 2b2373992d42e6bf33ff0e564a378bd8d3dac283..a137820ab11cb610ff010b8b6b50c496c0cf5d60 100644
--- a/splitting.go
+++ b/splitting.go
@@ -13,9 +13,6 @@ import (
 
 var log = logging.Logger("chunk")
 
-// DefaultBlockSize is the chunk size that splitters produce (or aim to).
-var DefaultBlockSize int64 = 1024 * 256
-
 // A Splitter reads bytes from a Reader and creates "chunks" (byte slices)
 // that can be used to build DAG nodes.
 type Splitter interface {