diff --git a/Dockerfile b/Dockerfile
index dc03c83..67b82fa 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -220,7 +220,12 @@ RUN PG_CONFIG_H=/root/MobilityDB/build/pgtypes/pg_config.h \
         "$PG_CONFIG_H"
 
 # COMPILING: libmeos.a
-RUN cmake --build /root/MobilityDB/build --target meos --parallel "$(nproc)"
+# The install step produces the header this module compiles against. MEOS
+# assembles the installed <meos.h> rather than shipping the source one: it
+# splices the PostgreSQL-compat definitions and the de-prefixed base I/O into
+# it, so interval_in, date_in and their siblings are declared only there.
+RUN cmake --build /root/MobilityDB/build --target meos --parallel "$(nproc)" \
+    && cmake --install /root/MobilityDB/build --prefix /root/meos-install
 
 # EMCC: link everything into meos.js + meos.wasm
 #
@@ -264,7 +269,7 @@ RUN mkdir -p /app/wasm \
         /root/gsl-wasm/lib/libgslcblas.a \
         /root/json-c-install/lib/libjson-c.a \
         /root/h3-install/lib/libh3.a \
-        -I/root/MobilityDB/meos/include \
+        -I/root/meos-install/include \
         -I/root/geos/include \
         -I/root/geos/build/capi \
         -I/root/MobilityDB/pgtypes \
diff --git a/codegen/res/bindings_c_header.c.template b/codegen/res/bindings_c_header.c.template
index 815c573..ecd4463 100644
--- a/codegen/res/bindings_c_header.c.template
+++ b/codegen/res/bindings_c_header.c.template
@@ -1,7 +1,21 @@
 
 #include <stdlib.h>
-#include <postgres.h>
-#include <utils/timestamp.h>
+#include <string.h>
+/*
+ * <meos.h> stands in for <postgres.h> here, and including both breaks it.
+ *
+ * The installed <meos.h> is assembled rather than copied from the source tree:
+ * MEOS splices its PostgreSQL-compat definitions into it under `#ifndef
+ * POSTGRES_H`, which supplies Datum, DateADT, TimestampTz, Interval and the
+ * de-prefixed base I/O (interval_in, date_in, timestamptz_in, …) that carry no
+ * meos_ prefix precisely so they do not collide with a real PostgreSQL. Pulling
+ * in the vendored <postgres.h> first defines POSTGRES_H, the spliced block is
+ * skipped, and those types and declarations vanish.
+ *
+ * So the module compiles against the installed umbrella alone. Only the Datum
+ * accessors are missing from it, and they are defined below beside the
+ * Int64GetDatum/Float8GetDatum this file already supplies for the same reason.
+ */
 #include <meos.h>
 #include <meos_geo.h>
 #include <meos_cbuffer.h>
@@ -14,23 +28,62 @@
 #include <emscripten.h>
 
 /*
- * Implementations of Int64GetDatum and Float8GetDatum required when
- * USE_FLOAT8_BYVAL is disabled (by-reference mode for 64-bit types).
+ * The Datum accessors PostgreSQL declares in postgres.h.
+ *
+ * Whether a 64-bit value rides inside a Datum or behind a pointer is decided by
+ * the pointer width: PostgreSQL sets USE_FLOAT8_BYVAL when SIZEOF_VOID_P >= 8,
+ * and Datum is uintptr_t. This module builds with -sMEMORY64=1, so pointers are
+ * 8 bytes and a TimestampTz or an int64 span bound rides inside the Datum
+ * itself. Reading such a Datum through a pointer returns whatever the value
+ * happens to address, which is how a bigint span reports a neighbour it does
+ * not touch as adjacent.
+ *
+ * The condition below reproduces PostgreSQL's, so both widths stay correct.
  */
-#ifndef USE_FLOAT8_BYVAL
-Datum Int64GetDatum(int64 X) {
+#include <stdint.h>
+
+typedef double float8;
+
+#if UINTPTR_MAX > 0xFFFFFFFFu
+#define USE_FLOAT8_BYVAL 1
+#endif
+
+#ifndef PointerGetDatum
+#define PointerGetDatum(X)  ((Datum) (X))
+#endif
+
+#ifdef USE_FLOAT8_BYVAL
+
+#define DatumGetInt64(X)  ((int64) (X))
+#define Int64GetDatum(X)  ((Datum) (X))
+
+static inline Datum Float8GetDatum(float8 X) {
+    union { float8 value; int64 retval; } myunion;
+    myunion.value = X;
+    return (Datum) myunion.retval;
+}
+
+#else
+
+#define DatumGetInt64(X)  (*((int64 *) DatumGetPointer(X)))
+
+static inline Datum Int64GetDatum(int64 X) {
     int64 *ptr = (int64 *) malloc(sizeof(int64));
     *ptr = X;
     return PointerGetDatum(ptr);
 }
 
-Datum Float8GetDatum(float8 X) {
+static inline Datum Float8GetDatum(float8 X) {
     float8 *ptr = (float8 *) malloc(sizeof(float8));
     *ptr = X;
     return PointerGetDatum(ptr);
 }
+
 #endif
 
+#define DatumGetTimestampTz(X)  ((TimestampTz) DatumGetInt64(X))
+#define TimestampTzGetDatum(X)  Int64GetDatum(X)
+
 /* --- Error handler --- */
 /*
  * A static C error handler stores the last errlevel/errcode/errmsg produced
diff --git a/core/c-src/bindings.c b/core/c-src/bindings.c
index f14637c..e1d0fb2 100644
--- a/core/c-src/bindings.c
+++ b/core/c-src/bindings.c
@@ -1,8 +1,22 @@
 /* AUTO-GENERATED - DO NOT EDIT. Run: npm run generate */
 
 #include <stdlib.h>
-#include <postgres.h>
-#include <utils/timestamp.h>
+#include <string.h>
+/*
+ * <meos.h> stands in for <postgres.h> here, and including both breaks it.
+ *
+ * The installed <meos.h> is assembled rather than copied from the source tree:
+ * MEOS splices its PostgreSQL-compat definitions into it under `#ifndef
+ * POSTGRES_H`, which supplies Datum, DateADT, TimestampTz, Interval and the
+ * de-prefixed base I/O (interval_in, date_in, timestamptz_in, …) that carry no
+ * meos_ prefix precisely so they do not collide with a real PostgreSQL. Pulling
+ * in the vendored <postgres.h> first defines POSTGRES_H, the spliced block is
+ * skipped, and those types and declarations vanish.
+ *
+ * So the module compiles against the installed umbrella alone. Only the Datum
+ * accessors are missing from it, and they are defined below beside the
+ * Int64GetDatum/Float8GetDatum this file already supplies for the same reason.
+ */
 #include <meos.h>
 #include <meos_geo.h>
 #include <meos_cbuffer.h>
@@ -15,23 +29,62 @@
 #include <emscripten.h>
 
 /*
- * Implementations of Int64GetDatum and Float8GetDatum required when
- * USE_FLOAT8_BYVAL is disabled (by-reference mode for 64-bit types).
+ * The Datum accessors PostgreSQL declares in postgres.h.
+ *
+ * Whether a 64-bit value rides inside a Datum or behind a pointer is decided by
+ * the pointer width: PostgreSQL sets USE_FLOAT8_BYVAL when SIZEOF_VOID_P >= 8,
+ * and Datum is uintptr_t. This module builds with -sMEMORY64=1, so pointers are
+ * 8 bytes and a TimestampTz or an int64 span bound rides inside the Datum
+ * itself. Reading such a Datum through a pointer returns whatever the value
+ * happens to address, which is how a bigint span reports a neighbour it does
+ * not touch as adjacent.
+ *
+ * The condition below reproduces PostgreSQL's, so both widths stay correct.
  */
-#ifndef USE_FLOAT8_BYVAL
-Datum Int64GetDatum(int64 X) {
+#include <stdint.h>
+
+typedef double float8;
+
+#if UINTPTR_MAX > 0xFFFFFFFFu
+#define USE_FLOAT8_BYVAL 1
+#endif
+
+#ifndef PointerGetDatum
+#define PointerGetDatum(X)  ((Datum) (X))
+#endif
+
+#ifdef USE_FLOAT8_BYVAL
+
+#define DatumGetInt64(X)  ((int64) (X))
+#define Int64GetDatum(X)  ((Datum) (X))
+
+static inline Datum Float8GetDatum(float8 X) {
+    union { float8 value; int64 retval; } myunion;
+    myunion.value = X;
+    return (Datum) myunion.retval;
+}
+
+#else
+
+#define DatumGetInt64(X)  (*((int64 *) DatumGetPointer(X)))
+
+static inline Datum Int64GetDatum(int64 X) {
     int64 *ptr = (int64 *) malloc(sizeof(int64));
     *ptr = X;
     return PointerGetDatum(ptr);
 }
 
-Datum Float8GetDatum(float8 X) {
+static inline Datum Float8GetDatum(float8 X) {
     float8 *ptr = (float8 *) malloc(sizeof(float8));
     *ptr = X;
     return PointerGetDatum(ptr);
 }
+
 #endif
 
+#define DatumGetTimestampTz(X)  ((TimestampTz) DatumGetInt64(X))
+#define TimestampTzGetDatum(X)  Int64GetDatum(X)
+
 /* --- Error handler --- */
 /*
  * A static C error handler stores the last errlevel/errcode/errmsg produced