diff --git a/src/openzl/compress/segmenters/segmenter_numeric.c b/src/openzl/compress/segmenters/segmenter_numeric.c
index e1755f5d5..86651b574 100644
--- a/src/openzl/compress/segmenters/segmenter_numeric.c
+++ b/src/openzl/compress/segmenters/segmenter_numeric.c
@@ -3,6 +3,7 @@
 #include "openzl/compress/segmenters/segmenter_numeric.h"
 #include "openzl/common/assertion.h"
 #include "openzl/compress/private_nodes.h"
+#include "openzl/zl_selector.h" // ZL_LP_INVALID_PARAMID ...which is probably not where this constant should be
 
 ZL_Report SEGM_numeric(ZL_Segmenter* sctx)
 {
@@ -14,14 +15,23 @@ ZL_Report SEGM_numeric(ZL_Segmenter* sctx)
     size_t const width = ZL_Input_eltWidth(input);
     ZL_ASSERT(width == 1 || width == 2 || width == 4 || width == 8);
 
-    // Note: Currently, static chunk size.
-    // Tomorrow: global parameter, then local parameter.
-    size_t const chunkByteSizeMax = 16 << 20;
-    size_t const chunkEltSizeMax  = chunkByteSizeMax / width;
+    ZL_IntParam const chunkParam = ZL_Segmenter_getLocalIntParam(
+            sctx, ZL_SEGM_NUMERIC_CHUNK_BYTE_SIZE_MAX_PID);
+    size_t const chunkByteSizeMax =
+            (chunkParam.paramId != ZL_LP_INVALID_PARAMID)
+            ? (size_t)chunkParam.paramValue
+            : (16 << 20) /* default to 16MB */;
+    ZL_ERR_IF_LT(
+            chunkByteSizeMax,
+            width,
+            nodeParameter_invalid,
+            "chunk size must produce at least one element");
+    size_t const chunkEltSizeMax = chunkByteSizeMax / width;
 
-    // Note: Currently, static head graph.
-    // Tomorrow: selectable
-    ZL_GraphID const headGraph = ZL_GRAPH_NUMERIC_COMPRESS;
+    ZL_GraphIDList const customGraphs = ZL_Segmenter_getCustomGraphs(sctx);
+    ZL_GraphID const headGraph        = (customGraphs.nbGraphIDs >= 1)
+                   ? customGraphs.graphids[0]
+                   : ZL_GRAPH_NUMERIC_COMPRESS;
 
     size_t numElts = ZL_Input_numElts(input);
     while (numElts > chunkEltSizeMax) {
diff --git a/src/openzl/compress/segmenters/segmenter_numeric.h b/src/openzl/compress/segmenters/segmenter_numeric.h
index 90303d1b3..7efa58804 100644
--- a/src/openzl/compress/segmenters/segmenter_numeric.h
+++ b/src/openzl/compress/segmenters/segmenter_numeric.h
@@ -10,6 +10,8 @@ ZL_BEGIN_C_DECLS
 
 ZL_Report SEGM_numeric(ZL_Segmenter* sctx);
 
+#define ZL_SEGM_NUMERIC_CHUNK_BYTE_SIZE_MAX_PID 1
+
 #define SEGM_NUMERIC_DESC                                           \
     {                                                               \
         .name                = "!zl.segmenter_numeric",             \
diff --git a/tests/datagen/distributions/VecLengthDistribution.h b/tests/datagen/distributions/VecLengthDistribution.h
index 784b0c127..39f170474 100644
--- a/tests/datagen/distributions/VecLengthDistribution.h
+++ b/tests/datagen/distributions/VecLengthDistribution.h
@@ -16,7 +16,7 @@ class VecLengthDistribution : public Distribution<size_t> {
     explicit VecLengthDistribution(
             std::shared_ptr<RandWrapper> generator,
             size_t min,
-            size_t max = kMaxVecLength)
+            size_t max = (size_t)1u << 17)
             : Distribution<size_t>(generator), min_(min), max_(max)
     {
         if (min > max) {
@@ -57,8 +57,6 @@ class VecLengthDistribution : public Distribution<size_t> {
     }
 
    private:
-    static constexpr size_t kMaxVecLength = (size_t)1u << 17;
-
     const size_t min_;
     const size_t max_;
 };