diff --git a/doc/src/sgml/spi.sgml b/doc/src/sgml/spi.sgml
index 7581661fc4a..651930aa3d6 100644
--- a/doc/src/sgml/spi.sgml
+++ b/doc/src/sgml/spi.sgml
@@ -437,6 +437,15 @@ typedef struct SPITupleTable
      </listitem>
     </varlistentry>
 
+    <varlistentry>
+     <term><symbol>SPI_OK_MERGE</symbol></term>
+     <listitem>
+      <para>
+       if a <command>MERGE</command> was executed
+      </para>
+     </listitem>
+    </varlistentry>
+
     <varlistentry>
      <term><symbol>SPI_OK_INSERT_RETURNING</symbol></term>
      <listitem>
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index 29bc26669b0..1edbd4353f6 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -2029,6 +2029,10 @@ SPI_result_code_string(int code)
 			return "SPI_OK_REL_REGISTER";
 		case SPI_OK_REL_UNREGISTER:
 			return "SPI_OK_REL_UNREGISTER";
+		case SPI_OK_TD_REGISTER:
+			return "SPI_OK_TD_REGISTER";
+		case SPI_OK_MERGE:
+			return "SPI_OK_MERGE";
 	}
 	/* Unrecognized code ... return something useful ... */
 	sprintf(buf, "Unrecognized SPI code %d", code);
diff --git a/src/pl/tcl/pltcl.c b/src/pl/tcl/pltcl.c
index 0dd6d8ab2c2..11f1ff19139 100644
--- a/src/pl/tcl/pltcl.c
+++ b/src/pl/tcl/pltcl.c
@@ -2442,6 +2442,7 @@ pltcl_process_SPI_result(Tcl_Interp *interp,
 		case SPI_OK_INSERT:
 		case SPI_OK_DELETE:
 		case SPI_OK_UPDATE:
+		case SPI_OK_MERGE:
 			Tcl_SetObjResult(interp, Tcl_NewWideIntObj(ntuples));
 			break;