diff --git a/src/bin/psql/t/001_basic.pl b/src/bin/psql/t/001_basic.pl
index 3961e69e1cc..bbd330216ae 100644
--- a/src/bin/psql/t/001_basic.pl
+++ b/src/bin/psql/t/001_basic.pl
@@ -452,6 +452,8 @@ psql_fails_like(
 	'\set WATCH_INTERVAL 1e500',
 	qr/is out of range/,
 	'WATCH_INTERVAL variable is out of range');
+psql_like($node, '\echo :WATCH_INTERVAL',
+	qr/^2$/m, 'WATCH_INTERVAL variable was not altered');
 
 # Test \g output piped into a program.
 # The program is perl -pe '' to simply copy the input to the output.
diff --git a/src/bin/psql/variables.c b/src/bin/psql/variables.c
index f2a28bc9820..8060f2959cc 100644
--- a/src/bin/psql/variables.c
+++ b/src/bin/psql/variables.c
@@ -224,6 +224,7 @@ ParseVariableDouble(const char *value, const char *name, double *result, double
 			if (name)
 				pg_log_error("invalid value \"%s\" for variable \"%s\": must be less than %.2f",
 							 value, name, max);
+			return false;
 		}
 		*result = dblval;
 		return true;