diff --git a/src/main/java/com/ibm/cldk/neo4j/V2GraphProjector.java b/src/main/java/com/ibm/cldk/neo4j/V2GraphProjector.java
index f019b3a6..c8c06452 100644
--- a/src/main/java/com/ibm/cldk/neo4j/V2GraphProjector.java
+++ b/src/main/java/com/ibm/cldk/neo4j/V2GraphProjector.java
@@ -147,14 +147,14 @@ public static GraphRows project(Analysis analysis, String appName) {
             for (JIdEdge e : analysis.getApplication().getParamIn()) {
                 b.edgeIfBothResolved("J_PARAM_IN",
                         new NodeRef("JBodyNode", "id", e.getSrc()),
-                        new NodeRef("JBodyNode", "id", e.getDst()), RowBuilder.props());
+                        new NodeRef("JBodyNode", "id", e.getDst()), paramEdgeProps(e));
             }
         }
         if (analysis.getApplication().getParamOut() != null) {
             for (JIdEdge e : analysis.getApplication().getParamOut()) {
                 b.edgeIfBothResolved("J_PARAM_OUT",
                         new NodeRef("JBodyNode", "id", e.getSrc()),
-                        new NodeRef("JBodyNode", "id", e.getDst()), RowBuilder.props());
+                        new NodeRef("JBodyNode", "id", e.getDst()), paramEdgeProps(e));
             }
         }
 
@@ -731,4 +731,14 @@ private static Map<String, Object> mapOf(String k, Object v) {
         m.put(k, v);
         return m;
     }
+
+    /**
+     * {@code var} on a param edge: the callee-side formal's variable, which the catalog declares
+     * and every {@code param_in}/{@code param_out} edge carries (codeanalyzer-python#195).
+     */
+    private static Map<String, Object> paramEdgeProps(JIdEdge e) {
+        Map<String, Object> p = RowBuilder.props();
+        p.put("var", e.getVar());
+        return RowBuilder.prune(p);
+    }
 }
diff --git a/src/main/java/com/ibm/cldk/schema/JIdEdge.java b/src/main/java/com/ibm/cldk/schema/JIdEdge.java
index a0fdaf0f..239de7eb 100644
--- a/src/main/java/com/ibm/cldk/schema/JIdEdge.java
+++ b/src/main/java/com/ibm/cldk/schema/JIdEdge.java
@@ -3,11 +3,18 @@
 import lombok.Data;
 
 /**
- * An id-to-id edge with no payload — the shape of {@code param_in}/{@code param_out} (application
- * scope, global-ordinal endpoints) and {@code summary} (callable scope, local endpoints).
+ * An id-to-id edge — the shape of {@code param_in}/{@code param_out} (application scope,
+ * global-ordinal endpoints) and {@code summary} (callable scope, local endpoints).
+ *
+ * <p>{@code var} is the callee-side formal's variable on a {@code param_in}/{@code param_out}
+ * edge — the parameter name, or {@code $ret} for the return port — set on every such edge. The
+ * Neo4j catalog declared it on {@code J_PARAM_IN}/{@code J_PARAM_OUT} while nothing wrote it, so
+ * a Cypher predicate on {@code r.var} went three-valued across every call boundary
+ * (codeanalyzer-python#195). Absent (never null-serialized) on {@code summary} edges.
  */
 @Data
 public class JIdEdge {
     private String src;
     private String dst;
+    private String var;
 }
diff --git a/src/main/java/com/ibm/cldk/syntactic_analysis/dataflow/SdgVertices.java b/src/main/java/com/ibm/cldk/syntactic_analysis/dataflow/SdgVertices.java
index 1227400a..a1ef5746 100644
--- a/src/main/java/com/ibm/cldk/syntactic_analysis/dataflow/SdgVertices.java
+++ b/src/main/java/com/ibm/cldk/syntactic_analysis/dataflow/SdgVertices.java
@@ -118,13 +118,14 @@ private static void addActualsAndEdges(
                 for (int i = 0; i < nArgs; i++) {
                     int formalIndex = Math.min(i, calleeParams - 1);
                     paramIn.add(edge(
-                            global(c, local + "/actual_in:" + i), global(callee, "@formal_in:" + formalIndex)));
+                            global(c, local + "/actual_in:" + i), global(callee, "@formal_in:" + formalIndex),
+                            callee.getParameters().get(formalIndex).getName()));
                 }
             }
             // Recomputed rather than read off callee.getBody(): traversal order is not call order, so
             // the callee's own addFormals may not have run yet when the caller's site is processed.
             if (hasActualOut && returnsValue(callee)) {
-                paramOut.add(edge(global(callee, "@formal_out"), global(c, local + "/actual_out")));
+                paramOut.add(edge(global(callee, "@formal_out"), global(c, local + "/actual_out"), "$ret"));
             }
         }
     }
@@ -143,6 +144,13 @@ private static JBodyNode vertex(String kind, String of, String parent) {
         return n;
     }
 
+    /** A param edge names the callee-side formal it binds: the parameter, or {@code $ret}. */
+    private static JIdEdge edge(String src, String dst, String var) {
+        JIdEdge e = edge(src, dst);
+        e.setVar(var);
+        return e;
+    }
+
     private static JIdEdge edge(String src, String dst) {
         JIdEdge e = new JIdEdge();
         e.setSrc(src);
diff --git a/src/test/java/com/ibm/cldk/neo4j/V2Neo4jSchemaConformanceTest.java b/src/test/java/com/ibm/cldk/neo4j/V2Neo4jSchemaConformanceTest.java
index a9b94333..0512d62c 100644
--- a/src/test/java/com/ibm/cldk/neo4j/V2Neo4jSchemaConformanceTest.java
+++ b/src/test/java/com/ibm/cldk/neo4j/V2Neo4jSchemaConformanceTest.java
@@ -40,6 +40,7 @@
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedHashMap;
@@ -165,6 +166,30 @@ public void everyEmittedNodeLabelAndPropertyIsDeclared() {
         }
     }
 
+    /**
+     * codeanalyzer-python#195, same defect here: the catalog declared {@code var} on
+     * J_PARAM_IN/J_PARAM_OUT and the projection wrote no properties, so a predicate on
+     * {@code r.var} went three-valued across every call boundary. Every emitted edge of those
+     * types carries every declared property — on all of them, not some.
+     */
+    @Test
+    public void paramEdgesCarryEveryDeclaredProperty() {
+        for (String rel : Arrays.asList("J_PARAM_IN", "J_PARAM_OUT")) {
+            int seen = 0;
+            for (EdgeRow e : rows.edges) {
+                if (!e.type.equals(rel)) {
+                    continue;
+                }
+                seen++;
+                for (String key : REL_BY_TYPE.get(rel).properties.keySet()) {
+                    assertTrue(e.props.containsKey(key) && e.props.get(key) != null,
+                            rel + " " + e.from.value + " -> " + e.to.value + " lacks " + key);
+                }
+            }
+            assertTrue(seen > 0, "precondition: the L4 fixture must emit " + rel);
+        }
+    }
+
     @Test
     public void everyEmittedRelationshipIsDeclared() {
         assertTrue(rows.edges.size() > 0, "fixture produced no edges");
diff --git a/src/test/java/com/ibm/cldk/syntactic_analysis/dataflow/SdgVerticesTest.java b/src/test/java/com/ibm/cldk/syntactic_analysis/dataflow/SdgVerticesTest.java
index b706eba8..40628399 100644
--- a/src/test/java/com/ibm/cldk/syntactic_analysis/dataflow/SdgVerticesTest.java
+++ b/src/test/java/com/ibm/cldk/syntactic_analysis/dataflow/SdgVerticesTest.java
@@ -82,9 +82,11 @@ void buildsFormalActualVerticesAndParamEdges() {
         JIdEdge in = r.paramIn.get(0);
         assertEquals(CanId.ordinalId(A_ID, "3:16/actual_in:0"), in.getSrc());
         assertEquals(CanId.ordinalId(B_ID, "formal_in:0"), in.getDst());
+        assertEquals("y", in.getVar(), "param_in names the callee formal it binds (#195)");
         assertEquals(1, r.paramOut.size());
         assertEquals(CanId.ordinalId(B_ID, "formal_out"), r.paramOut.get(0).getSrc());
         assertEquals(CanId.ordinalId(A_ID, "3:16/actual_out"), r.paramOut.get(0).getDst());
+        assertEquals("$ret", r.paramOut.get(0).getVar(), "param_out names the return port");
     }
 
     @Test