diff --git a/src/backend/catalog/objectaddress.c b/src/backend/catalog/objectaddress.c
index b08e076e65f..c1b2e84146b 100644
--- a/src/backend/catalog/objectaddress.c
+++ b/src/backend/catalog/objectaddress.c
@@ -4064,7 +4064,9 @@ getObjectDescription(const ObjectAddress *object, bool missing_ok)
 			}
 
 		default:
-			elog(ERROR, "unsupported object class: %u", object->classId);
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("unsupported object class: %u", object->classId)));
 	}
 
 	/* an empty buffer is equivalent to no object found */
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 8dc70bfa0f1..5a2c9f02bf6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -9621,6 +9621,7 @@ ATPrepAddPrimaryKey(List **wqueue, Relation rel, AlterTableCmd *cmd,
 				tup = findNotNullConstraint(childrelid, strVal(column));
 				if (!tup)
 					ereport(ERROR,
+							errcode(ERRCODE_INVALID_TABLE_DEFINITION),
 							errmsg("column \"%s\" of table \"%s\" is not marked NOT NULL",
 								   strVal(column), get_rel_name(childrelid)));
 				/* verify it's good enough */
diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c
index f838311090b..f0c7755b8fb 100644
--- a/src/backend/parser/parse_utilcmd.c
+++ b/src/backend/parser/parse_utilcmd.c
@@ -805,8 +805,10 @@ transformColumnDefinition(CreateStmtContext *cxt, ColumnDef *column)
 					if (constraint->conname &&
 						notnull_constraint->conname &&
 						strcmp(notnull_constraint->conname, constraint->conname) != 0)
-						elog(ERROR, "conflicting not-null constraint names \"%s\" and \"%s\"",
-							 notnull_constraint->conname, constraint->conname);
+						ereport(ERROR,
+								errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+								errmsg("conflicting not-null constraint names \"%s\" and \"%s\"",
+									   notnull_constraint->conname, constraint->conname));
 
 					if (notnull_constraint->is_no_inherit != constraint->is_no_inherit)
 						ereport(ERROR,
diff --git a/src/backend/storage/ipc/shmem.c b/src/backend/storage/ipc/shmem.c
index f971ee24192..f78c34daee1 100644
--- a/src/backend/storage/ipc/shmem.c
+++ b/src/backend/storage/ipc/shmem.c
@@ -1210,7 +1210,9 @@ pg_get_shmem_allocations_numa(PG_FUNCTION_ARGS)
 	Size	   *nodes;
 
 	if (pg_numa_init() == -1)
-		elog(ERROR, "libnuma initialization failed or NUMA is not supported on this platform");
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("libnuma initialization failed or NUMA is not supported on this platform")));
 
 	InitMaterializedSRF(fcinfo, 0);
 
diff --git a/src/backend/utils/adt/acl.c b/src/backend/utils/adt/acl.c
index a01d8f4bc41..913d715a8c8 100644
--- a/src/backend/utils/adt/acl.c
+++ b/src/backend/utils/adt/acl.c
@@ -989,7 +989,16 @@ acldefault_sql(PG_FUNCTION_ARGS)
 			objtype = OBJECT_TYPE;
 			break;
 		default:
-			elog(ERROR, "unrecognized object type abbreviation: %c", objtypec);
+			/* Avoid printing non-ASCII bytes, else we have encoding issues */
+			if (objtypec >= ' ' && objtypec < 0x7f)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+						 errmsg("unrecognized object type abbreviation: \"%c\"", objtypec)));
+			else				/* use \ooo format, like charout() */
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+						 errmsg("unrecognized object type abbreviation: \"\\%03o\"",
+								(unsigned char) objtypec)));
 	}
 
 	PG_RETURN_ACL_P(acldefault(objtype, owner));
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 8ef16c9ad4c..43efa548452 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -1186,7 +1186,9 @@ intervaltypmodout(PG_FUNCTION_ARGS)
 			fieldstr = "";
 			break;
 		default:
-			elog(ERROR, "invalid INTERVAL typmod: 0x%x", typmod);
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("unrecognized interval typmod: %d", typmod)));
 			fieldstr = "";
 			break;
 	}
@@ -1246,7 +1248,9 @@ intervaltypmodleastfield(int32 typmod)
 		case INTERVAL_FULL_RANGE:
 			return 0;			/* SECOND */
 		default:
-			elog(ERROR, "invalid INTERVAL typmod: 0x%x", typmod);
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("unrecognized interval typmod: %d", typmod)));
 			break;
 	}
 	return 0;					/* can't get here, but keep compiler quiet */
@@ -1489,7 +1493,9 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 			/* fractional-second rounding will be dealt with below */
 		}
 		else
-			elog(ERROR, "unrecognized interval typmod: %d", typmod);
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("unrecognized interval typmod: %d", typmod)));
 
 		/* Need to adjust sub-second precision? */
 		if (precision != INTERVAL_FULL_PRECISION)
diff --git a/src/pl/plpgsql/src/pl_gram.y b/src/pl/plpgsql/src/pl_gram.y
index 5e14a2d7302..37785f58cc2 100644
--- a/src/pl/plpgsql/src/pl_gram.y
+++ b/src/pl/plpgsql/src/pl_gram.y
@@ -393,7 +393,9 @@ comp_option		: '#' K_OPTION K_DUMP
 						else if (strcmp($3, "off") == 0)
 							plpgsql_curr_compile->print_strict_params = false;
 						else
-							elog(ERROR, "unrecognized print_strict_params option %s", $3);
+							ereport(ERROR,
+									(errcode(ERRCODE_SYNTAX_ERROR),
+									 errmsg("unrecognized %s option \"%s\"", "print_strict_params", $3)));
 					}
 				| '#' K_VARIABLE_CONFLICT K_ERROR
 					{