diff --git a/codegen/src/main/java/FunctionsGenerator.java b/codegen/src/main/java/FunctionsGenerator.java
index 7dec7998f..1ac115fcc 100644
--- a/codegen/src/main/java/FunctionsGenerator.java
+++ b/codegen/src/main/java/FunctionsGenerator.java
@@ -38,11 +38,6 @@ public class FunctionsGenerator {
     private static final Set<String> DATE_C_TYPES = Set.of("DateADT");
     private static final Set<String> TIMESTAMP_C_TYPES = Set.of("Timestamp", "TimestampTz");
 
-    // The JSON sometimes encodes them as int32_t rather than size_t, producing
-    // "int" in the interface.  old_functions.txt used "long" consistently for these,
-    // so we force long when the interface type resolved to int for these names.
-    private static final Set<String> SIZE_PARAM_NAMES = Set.of("size", "wkb_size");
-
     /** Name of the leading parameter carrying the address of a struct returned through memory. */
     private static final String RESULT_PARAM = "_result_address";
 
@@ -509,12 +504,6 @@ private FunctionDef parseFunctionDef(JsonNode fn) {
                     String pCType = p.get("cType").asText();
                     String pJava  = mapCTypeToJava(pCType);
 
-                    // Override int → long for known byte-count parameters.
-                    // The JSON may emit int32_t for these; old_functions.txt used long.
-                    if (SIZE_PARAM_NAMES.contains(pName) && pJava.equals("int")) {
-                        pJava = "long";
-                    }
-
                     params.add(new ParamDef(pName, pJava, pCType, outParams.contains(rawName)));
                 }
             }
@@ -999,10 +988,6 @@ private String generateStaticMethod(FunctionDef fn, int partIndex) {
                 continue; // hide from signature; allocated below
             }
             String wrapperType = mapCTypeToJavaWrapper(p.cType);
-            // Preserve the long override for size params
-            if (SIZE_PARAM_NAMES.contains(p.name) && wrapperType.equals("int")) {
-                wrapperType = "long";
-            }
             boolean needsConversion = isTemporalCType(p.cType);
             wparams.add(new WrapperParam(p.name, wrapperType, p.javaType, needsConversion));
         }
@@ -1199,10 +1184,7 @@ private String buildInterfaceParamList(List<ParamDef> params) {
         if (params.isEmpty()) return "";
         StringJoiner sj = new StringJoiner(", ");
         for (ParamDef p : params) {
-            // Restore long for size params even at interface level
-            String type = SIZE_PARAM_NAMES.contains(p.name) && p.javaType.equals("int")
-                    ? "long" : p.javaType;
-            sj.add(type + " " + p.name);
+            sj.add(p.javaType + " " + p.name);
         }
         return sj.toString();
     }
diff --git a/codegen/src/test/java/FunctionsGeneratorTest.java b/codegen/src/test/java/FunctionsGeneratorTest.java
index 96ecafd48..33a149fe8 100644
--- a/codegen/src/test/java/FunctionsGeneratorTest.java
+++ b/codegen/src/test/java/FunctionsGeneratorTest.java
@@ -806,27 +806,28 @@ void javaKeywordParam() throws Exception {
         }
 
         @Test
-        @DisplayName("size/wkb_size params use long in interface")
-        void sizeLongOverride() throws Exception {
+        @DisplayName("a parameter takes the Java type of its C type whatever its name")
+        void paramTypeFollowsCTypeNotName() throws Exception {
             String json = """
                 {
                   "functions": [{
-                    "name": "tsequence_make",
-                    "returnType": {"c": "TSequence *"},
+                    "name": "tint_value_split",
+                    "returnType": {"c": "Temporal **"},
                     "params": [
-                      {"name": "instants", "cType": "TInstant **"},
-                      {"name": "size",     "cType": "int32_t"},
-                      {"name": "lower_inc","cType": "bool"},
-                      {"name": "upper_inc","cType": "bool"},
-                      {"name": "interp",   "cType": "interpType"},
-                      {"name": "normalize","cType": "bool"}
+                      {"name": "temp",     "cType": "const Temporal *"},
+                      {"name": "size",     "cType": "int"},
+                      {"name": "wkb_size", "cType": "int32_t"},
+                      {"name": "vsize",    "cType": "size_t"}
                     ]
                   }]
                 }
                 """;
             String out = generateFromJson(json);
-            // 'size' must be long even though cType is int32_t
-            assertTrue(out.contains("long size"));
+            assertTrue(out.contains("int size"));
+            assertTrue(out.contains("int wkb_size"));
+            assertTrue(out.contains("long vsize"));
+            assertFalse(out.contains("long size"));
+            assertFalse(out.contains("long wkb_size"));
         }
 
         @Test